ALBERT

Beschreibung: Beet Armyworm, Spodoptera exigua is a herbivorous moth and a serious pest of many economically important plants, which are used as food sources. Because of rigorous standards of food quality, usage of synthetic insecticides in crop protection, against pests, is limited. Solanaceae plant extracts may be a relatively cheap source of efficient natural insecticides that can limit usage of synthetic substances. Their biological activity is not fully known. In particular, ultrastructural studies, using transmission electron microscopy, are not usual. In the present article we describe the effects of sublethal concentrations of tomato and potato leaf extracts against S. exigua . Acute lethal effects were not observed. Both extracts exerted similar effects within midgut and fat body cells. Midgut cells were not significantly altered while fat body cells showed prominent swelling of nuclear envelope and endoplasmic reticulum, vacuolization of mitochondria and fusion of fat droplets. These changes were much more intensive within groups exposed to potato than tomato extracts at highest concentration at least. Light microscopy was used to observe and document developmental alterations of S. exigua exposed to potato and tomato leaf extracts. Potato leaf extracts significantly decreased hatching success and caused morphological malformations of imagoes. Among them, malformations of wings were the most prominent. Interestingly, these effects were not observed within populations exposed to tomato extracts at highest concentration at least.

Beschreibung: Surface ultrastructure of the gills of the angler catfish Chaca chaca was investigated to unravel the adaptive modifications associated with the feeding ecology of the fish. The fish is often found in mud or in soft substrates where they remain buried both for protection and to feed. Gill rakers present on the gill arch in most fish species are absent in this fish. The absence of gill rakers are associated with the feeding habit of the fish and is considered to facilitate the swallowing of captured prey smoothly without any hindrance. Highly corrugated surface of the gill arch and gill filaments could be associated to retain water/mucus to prevent dessicassion of the fish. Papillae like epithelial protuberances each bearing a taste bud at its summit toward the pharyngeal side of the gill arch is associated with the sorting of the food. Large number of mucous goblet cells on the gill arch epithelium are considered to secret copious mucus to lubricate the prey for easy swallowing. In C. chaca the gill septa between gill filaments are reduced. This could enhance the flexibility and permit the free movement of the gill filaments. Extensive secondary lamellae and infrequent mucous goblet cells on secondary lamellae are associated to increase the surface area to enhance efficiency of gaseous exchange.

Beschreibung: In the present research, different adhesive techniques were used to set up fillings with composite resins. After the application of etch and rinse or self etch adhesive technique, marginal adaptation of composite fillings was estimated by the length of margins without gaps, and by the microretention of resin in enamel and dentin. The study material consisted of 40 extracted teeth. Twenty Class V cavities were treated with 35% phosphorous acid and restored after rinsing by Adper Single Bond 2 and Filtek Ultimate - ASB/FU 3M ESPE composite system. The remaining 20 cavities were restored by Adper Easy One - AEO/FU 3M ESPE composite system. Marginal adaptation of composite fillings was examined using a scanning electron microscope (SEM). The etch and rinse adhesive technique showed a significantly higher percentage of margin length without gaps (in enamel: 92.5%, in dentin: 57.3%), compared with the self-etch technique with lower percentage of margin length without gaps, in enamel 70.4% ( p  〈 .001), and in dentin-22.6% ( p  〈 .05). In the first technique, microretention was composed of adhesive and hybrid layers as well as resin tugs in interprismatic spaces of enamel, while the dentin microretention was composed of adhesive and hybrid layers with resin tugs in dentin canals. In the second technique, resin tugs were rarely seen and a microgap was dominant along the border of restoration margins. The SEM analysis showed a better marginal adaptation of composite resin to enamel and dentin with better microretention when the etch and rinse adhesive procedure was applied.

Beschreibung: The purpose of this study was to compare total-etch, self-etch, and selective etching techniques on the marginal microleakage of Class V composite restorations prepared by Er:YAG laser and bur. Class V cavities prepared on both buccal and lingual surfaces of 30 premolars by Er:YAG laser or bur and divided into six groups. The occlusal margins were in enamel, and the cervical margins were in cementum. Group-1: bur preparation(bp)+Adper Single Bond 2 (ASB)+Filtek Z550 (FZ); Group-2: laser preparation(lp)+(ASB)+(FZ); Group-3: bp + Clearfil S3 Bond Plus (CSBP)+(FZ); Group-4: lp+(CSBP) (FZ); Group-5: bp + acid etching+(CSBP)+(FZ); Group-6: lp + acid etching+(CSBP)+(FZ). All teeth were stored in distilled water at 37°C for 24 hr, and then thermocycled 1000 times (5–55°C). Five teeth from each group were chosen for the microleakage investigation, and two teeth for the scanning electron microscope evaluation. Teeth which were prepared for the microleakage test were immersed in .5% methylene blue dye for 24 hr. After immersion, the teeth were sectioned and observed under a stereomicroscope for dye penetration. Data were analyzed using Kruskal–Wallis and Mann–Whitney U tests ( p  〈 .05). More microleakage was observed in the cervical regions compared to the occlusal regions in Groups 3, 5, and 6, respectively ( p  〈 .05). There is no statistically significant difference in Groups 1, 2, and 4, in terms of cervical regions versus occlusal regions ( p  〉 .05). No significant differences were observed among any groups in terms of occlusal and cervical surfaces, separately ( p  〉 .05). Different etching techniques did not influence microleakage of Class V restorations prepared by Er:YAG laser and bur.

Beschreibung: Protein–membrane interactions are still an important topic of investigation. One of the suitable experimental techniques used by the scientific community to address such question is atomic force microscopy. In a previous work, we have reported that the binding mechanism between the cytolytic and antimicrobial protein (Cyt2Aa2) and lipid/cholesterol bilayers was concentration-dependent, leading to either the formation of holes in the bilayer or aggregates. Here we study such binding mechanism as a function of time at low protein concentrations (10 µg/mL). We demonstrate that although holes are formed during the first stages of the protein–lipid interaction, a reparation process due to molecular mobility in the bilayer leads to a homogenous and isotropic protein–lipid/cholesterol layer within 3 hr. The combination of imaging, force spectroscopy, and phase contrast delivered information about topography dynamics (molecular mobility), layer thickness, and mechanical properties of the protein–lipid/cholesterol system. These results highlight the importance of the observation time in (such type of) protein–lipid interactions (at low protein concentrations).

Beschreibung: Atomic force microscopy (AFM) is an enormous tool to observe nature in highest resolution and understand fundamental processes like friction and tribology on the nanoscale. Atomic resolution in highest quality was possible only in well-controlled environments like ultrahigh vacuum (UHV) or controlled buffer environments (liquid conditions) and more specified for long-term high-resolution analysis at low temperatures (∼4 K) in UHV where drift is nearly completely absent. Atomic resolution in these environments is possible and is widely used. However, in uncontrolled environments like air, with all its pollutants and aerosols, unspecified thin liquid films as thin as a single molecular water-layer of 200 pm or thicker condensation films with thicknesses up to hundred nanometer, have been a problem for highest resolution since the invention of the AFM. The goal of true atomic resolution on hydrophilic as well as hydrophobic samples was reached recently. In this manuscript we want to review the concept of ambient AFM with atomic resolution. The reader will be introduced to the phenomenology in ambient conditions and the problems will be explained and analyzed while a method for scan parameter optimization will be explained. Recently developed concepts and techniques how to reach atomic resolution in air and ultra-thin liquid films will be shown and explained in detail, using several examples.

Beschreibung: The visualization of taxonomically diagnostic features of individual pollen grains can be a challenge for many ecologically and phylogenetically important pollen types. The resolution of traditional optical microscopy is limited by the diffraction of light (250 nm), while high resolution tools such as electron microscopy are limited by laborious preparation and imaging workflows. Airyscan confocal superresolution and structured illumination superresolution (SR-SIM) microscopy are powerful new tools for the study of nanoscale pollen morphology and three-dimensional structure that can overcome these basic limitations. This study demonstrates their utility in capturing morphological details below the diffraction limit of light. Using three distinct pollen morphotypes ( Croton hirtus, Dactylis glomerata , and Helianthus sp.) and contrast-enhancing fluorescent staining, we were able to assess the effectiveness of the Airyscan and SR-SIM. We further demonstrate that these new superresolution methods can be easily applied to the study of fossil pollen material.

Beschreibung: Segmentation of objects from a noisy and complex image is still a challenging task that needs to be addressed. This article proposed a new method to detect and segment nuclei to determine whether they are malignant or not (determination of the region of interest, noise removal, enhance the image, candidate detection is employed on the centroid transform to evaluate the centroid of each object, the level set [LS] is applied to segment the nuclei). The proposed method consists of three main stages: preprocessing, seed detection, and segmentation. Preprocessing stage involves the preparation of the image conditions to ensure that they meet the segmentation requirements. Seed detection detects the seed point to be used in the segmentation stage, which refers to the process of segmenting the nuclei using the LS method. In this research work, 58 H&E breast cancer images from the UCSB Bio-Segmentation Benchmark dataset are evaluated. The proposed method reveals the high performance and accuracy in comparison to the techniques reported in literature. The experimental results are also harmonized with the ground truth images.

Beschreibung: In this paper, by applying the differential quadrature (DQ) method, a semi analytical model has been developed for atomic force microscope cantilever, and then by using the interfacial forces between the cantilever tip and imaged surfaces, a 2D model has been extracted for imaging nano-sized fine samples. By employing the present model, several simple and standard samples have been imaged, and finally the effects of the microcantilever's structural damping and its stiffness on the imaging results have been investigated. It has been observed that, through the control of damping, the quality of the acquired images is considerably improved. It has also been shown that the self-softening and self-hardening properties of cantilever have serious effects on the obtained images. The present model can be used to study the effects of different parameters on the process of imaging small-scale samples. Also, as one of its most important applications, this model can be used in common multiscale models for simulating and predicting the effects of large and small fields on each other.

Beschreibung: Three-dimensional optical super-resolution imaging is capable of providing 3D visualization of cellular structures in nanoscale detail. The past decade has witnessed the blossoming of 3D super-resolution imaging technologies. In this review, we comprehensively discuss and compare the imaging depth, resolution enhancement, and imaging speed of the existing 3D super-resolution imaging techniques.

Beschreibung: Reversible photoswitching has been proposed as a way to identify molecules that are present in small numbers over a large, non-switching, background. This approach, called optical-lock-in-detection (OLID) requires the deterministic control of the fluorescence of a photochromic emitter through optical modulation between a bright (on) and a dark state (off). OLID yields a high-contrast map where the switching molecules are pinpointed, but the fractional intensities of the emitters are not returned. The present work presents a modified OLID approach (quantitative OLID or qOLID) that yields quantitative information of the switching (f SW ) and non-switching (f NS ) components. After the validation of the method with a sample dataset and image sequence, we apply qOLID to measurements in cells that transiently express the photochromic protein EYQ1. We show that qOLID is efficient in separating the modulated from the non-modulated signal, the latter deriving from background/autofluorescence or fluorophores emitting in the same spectral region. Finally, we apply qOLID to Förster (Fluorescence) Resonance Energy Transfer (FRET) imaging. We here demonstrate that qOLID is able to highlight the distribution of FRET intensity in a sample by using a photochromic donor and a non-photochromic acceptor.

Beschreibung: Introduction Pregnancy-related deep vein thrombosis (DVT) is most common during the late phase of pregnancy and the first 6-weeks postpartum. Pregnancy-related DVT can have long-term complications, specifically post-thrombotic syndrome (PTS). Fibrin network ultrastructure is altered during pregnancy and post-partum. It is therefore essential to evaluate fibrin fiber diameter during and after pregnancy as this may provide insight into pregnancy-related DVT and subsequent PTS. Materials and methods The fibrin network ultrastructure of females during different phases of pregnancy was compared to that of non-pregnant females to assess possible changes to the fibrin network morphology and fibrin fiber diameter using scanning electron microscopy micrographs. Results The fibrin network arrangement was more densely packed during different phases of pregnancy, corresponding to earlier findings. Fibrin diameter decreased significantly during pregnancy, with the greatest decrease occurring during the late phase of pregnancy. The fractal dimensions of fibrin micrographs increased significantly during pregnancy compared to nonpregnant females. These changes are indicative of a simultaneous hypercoagulable and hypofibrinolytic state and correspond to the increased risk of DVT and subsequent development of PTS. Conclusion It is critical to identify “vulnerable” females with an inflammatory predisposition to prevent possible DVT and subsequent PTS. Modifiable risk factors like obesity and smoking should be addressed to alleviate the burden on the coagulation system. Morphological and viscoelastic techniques are crucial in assessing the coagulatory health of females during pregnancy.

Beschreibung: Objectives Chemotherapy targets rapidly dividing tissues in the body. It destroys the progenitor cells in gonads resulting in premature ovarian failure. Studies have suggested that bone marrow-derived stem cells can generate oocytes in chemotherapy treated female rats after transplantation. The present study aimed to assess mechanism of homing, the action of injected BM-MSCs on ovarian function after ovarian damage. Experimental design : Seventy two female albino rats were randomly allocated into Control and CTX group, The Experimental protocol was lasted for 12 weeks during which serum FSH and E2 were monitored twice at the end of the 2nd week (12 rats) and 8th week (6 rats). Stem cells identification and homing were evaluated by Flowcytometry and tagging of stem cells with iron oxide particles respectively. Also, histopathological examination was done to evaluate both degeneration (6 rats at 4th week) and regeneration (6 rats at 12th week) of ovarian tissue together with assessment of the levels of TNF-α in ovarian homogenate and IGF-I as a growth factor in ovarian tissue. Principal observations : Partial improvement of E2 and FSH levels as well as ovarian architecture. Elevation of ovarian TNF- α levels and of IGF-I immunohistochemical expressions in ovarian tissues of BM-MSCs injected rats were noticed following homing of BM- MSCs in the ovarian stroma in both control and chemotherapy groups. Conclusion : Injected BM- MSCs can home in the stroma of the injured ovaries. IGF-I and TNF- α may have a role in the attraction of stem cells in vivo.

Beschreibung: Lasers and photodynamic therapy have been considered a convergence treatment for onychomycosis, which is a fungal infection on the nail bed and nail plate. Laser therapies have shown satisfactory results without significant complications for onychomycosis; however, the mechanism of clearing remains unknown. In this work, we investigated changes in the chemical structure of nail keratin induced by Nd:YAG laser using Raman spectroscopy. Toe nails with onychomycosis were treated with 1064 nm Nd:YAG laser. After laser treatment, the disulfide band (490–590 cm −1 ) of nail keratin was rarely observed or was reduced in intensity. The amide I band (1500–1700 cm −1 ) also showed changes induced by the laser. The α-helical (1652 cm −1 ) structures dominated the β-sheet (1673 cm −1 ) in nontreated nail, but the opposite phenomenon was observed after laser treatment.

Beschreibung: This note reports on the proper correction of force data acquired with an atomic force microscope (AFM). The force–time representation is hereby used to obtain the correction factors for the overall offset and slope for a single force–time curve, as the initial force, F 0  =  F ( t 0 ), and the rate of change in the force per unit of time, dF/dt , respectively. The report shows that a complete set of force data, including the approach, delay and retraction regions, can be simultaneously corrected in the force–time representation by subtracting the line CL t = F 0  +  dF/dt·t to the experimental data. The method described here outperforms the one commonly employed in the correction of AFM force curves and highlights the convenience of using the force–time representation for force data processing wherein the artifactual behavior can be expressed as a single, differentiable function of time.

Beschreibung: To better understand the basis of urinary calculi formation, we studied the composition, microstructure, and element analysis of different types of urinary calculi. Sixty people with urinary stones in Shanxi province were selected randomly. The composition of urinary stones was analyzed using Fourier transform infrared spectroscopy. The microstructure of material components was observed by a scanning electron microscopy and the elemental distribution and composition were analyzed by an X-ray energy spectrometer. Furthermore, general information, BMI, history of medicine, chronic medical history, family history, and recurrence rates were collected. Female-to-male ratio was 1:2.5; median age was 43.2 years old. Of the patients, 13.3% were found definite family history and 46.6% of patients for recurrence history. It was found that mixed stones account for the largest proportion (65%), followed by calcium oxalate monohydrate calculi (26.67%). In mixed stones, the mixture of calcium oxalate monohydrate and hydroxyapatite had the largest proportion, accounting for 71.79%. Stones showed different microcosmic characteristics and element distribution. Stones varied widely in distribution, infrared spectrum, microstructure, and element composition, which provided an important basis for urinary calculi research regarding urinary stone formation.

Beschreibung: The spatial resolution of a stimulated emission depletion (STED) microscope is theoretically unlimited and practically determined by the signal-to-noise ratio. Typically, an increase of the STED beam's power leads to an improvement of the effective resolution. However, this improvement may vanish because an increased STED beam's power is often accompanied by an increased photobleaching, which worsen the effective resolution by reducing the signal strength. A way to lower the photobleaching in pulsed STED (P-STED) implementations is to reduce the peak intensity lengthening the pulses duration (for a given average STED beam's power). This also leads to a reduction of the fluorophores quenching, thus a reduction of the effective resolution, but the time-gated detection was proved to be successful in recovering these reductions. Here we demonstrated that a subnanosecond fiber laser beam (pulse width ∼600 ps) reduces the photobleaching with respect to a traditional stretched hundreds picosecond (∼200 ps) beam provided by a Ti:Sapphire laser, without any effective spatial resolution lost.

Beschreibung: This study describes the mucosa-associated lymphoid tissue (MALT) in odontocetes from the Brazilian coast and freshwater systems. Seven species were evaluated and tissue samples were analyzed by light, scanning and transmission electron microscopy, and immunohistochemistry. Laryngeal tonsil was a palpable oval mass located in the larynx, composed of a lymphoepithelial complex. Dense collections of lymphocytes were found in the skin of male fetus and calf. Clusters of lymphoid tissue were found in the uterine cervix of a reproductively active juvenile female and along the pulmonary artery of an adult female. Lymphoid tissues associated with the gastrointestinal tract were characterized by diffusely arranged or organized lymphocytes. The anal tonsil was composed of an aggregate of lymphoid tissue occurring exclusively in the anal canal, being composed of squamous epithelium branches. MALT was present in different tissues and organic systems of cetaceans, providing constant protection against mucosal pathogens present in their environment.

Beschreibung: ABSTRACT With the development of spherical aberration (Cs) corrected scanning transmission electron microscopy (STEM), high angle annular dark filed (HAADF) imaging technique has been widely applied in the microstructure characterization of various advanced materials with atomic resolution. However, current qualitative interpretation of the HAADF image is not enough to extract all the useful information. Here a modified peaks finding method was proposed to quantify the HAADF-STEM image to extract structural and chemical information. Firstly, an automatic segmentation technique including numerical filters and watershed algorithm was used to define the sub-areas for each atomic column. Then a 2D Gaussian fitting was carried out to determine the atomic column positions precisely, which provides the geometric information at the unit-cell scale. Furthermore, a self-adaptive integration based on the column position and the covariance of statistical Gaussian distribution were performed. The integrated intensities show very high sensitivity on the mean atomic number with improved signal-to-noise ( S/N ) ratio. Consequently, the polarization map and strain distributions were rebuilt from a HAADF-STEM image of the rhombohedral and tetragonal BiFeO 3 interface and a MnO 2 monolayer in LaAlO 3 /SrMnO 3 /SrTiO 3 heterostructure was discerned from its neighbor TiO 2 layers. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT The ultrastructural study carried out on (a) oocytes of Armadillidium vulgare during vitellogenesis, (b) mature eggs taken from the ovaries during the parturial moult of the posterior half of the body, and (c) fertilized eggs collected within a few hours of their release into the brood pouch, has clearly demonstrated that before the fertilization the chorion is the only envelope present in the egg of oniscidean isopods. In the mature eggs, the chorion appears as a uniformly electron-dense lamina, about 0.4–0.5 µm thick, which does not show any specialized area. A second envelope, described by other authors as vitelline envelope, is formed above the oolemma only right after fertilization and appears separated from the chorion by a space full of liquid. The ways in which the genesis of this envelope is realized are not yet clear; it could be interpreted rather as a fertilization membrane. The investigations carried out with the aid of a battery of FITC-lectins have highlighted the presence at the chorion surface of unfertilized eggs of various saccharide residues distributed in uniform way. No significant change was observed in the pattern of lectins binding to the chorion of eggs taken from the brood pouch, thus demonstrating how, after the fertilization, no significant rearrangement in the distribution of saccharide residues present on the egg surface occurs in A. vulgare . The ways in which, therefore, the recognition, the binding and the entry of the peculiar sperm of oniscidean isopods into the egg occur, still remain all to be deciphered. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT The opossum Monodelphis domestica presents movement of the temporomandibular joint (TMJ) reflecting adaptation to eating habits similar to movement in humans, but the structure of the TMJ is not yet known. Thus, nine young M. domestica , of both sexes were weighed, anesthetized with xylazine (10 mg kg −1 ), and ketamine (70 mg kg −1 ) and processed for: 1. The analyses of the macroscopic angioarchitecture after latex injection, as well as the topography of the TMJ; 2. The analysis of microvascularization after injection of Mercox resin and corrosion of soft tissue with NaOH using scanning electron microscopy and; 3. The histological evaluation of the TMJ with an optical microscope. Macroscopic analysis of the latex injected vessels revealed the distribution of the arteries from the common carotid artery, receiving branches of the superficial temporal and maxillary arteries. The mandibular condyle has the long axis in the lateral–lateral direction, and is convex in the anterior–posterior direction. Its topography was determined in relation to the eye and external acoustic meatus. With scanning electron microscopy, microvascularization consists of arterioles of varying diameter (85–15 µm) of the meandering capillary network in the retrodiscal region, and a network of straight capillaries in the TMJ anterior region. Via light microscopy the TMJ has similar histological features to those of humans. These macroscopic, microscopic and ultrastructural data from TMJ of the M. domestica could be a suitable model for TMJ physiology and pathophysiology studies for then speculate on possible human studies. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: Oracle Bone Inscriptions in the Shang dynasty (1600–1046 BC) are the earliest well-developed writing forms of the Chinese character system, and their carving techniques have not been studied by tool marks analysis with microscopy. In this study, a digital microscope with three-dimensional surface reconstruction based on extended depth of focus technology was used to investigate tool marks on the surface of four pieces of oracle bones excavated at the eastern area of Huayuanzhuang, Yinxu site(ca., 1319–1046 BC), the last capital of the Shang dynasty, Henan province, China. The results show that there were two procedures to carve the characters on the analyzed tortoise shells. The first procedure was direct carving. The second was “outlining design,” which means to engrave a formal character after engraving a draft with a pointed tool. Most of the strokes developed by an engraver do not overlap the smaller draft, which implies that the outlining design would be a sound way to avoid errors such as wrong and missing characters. The strokes of these characters have different shape at two ends and variations on width and depth of the grooves. Moreover, the bottom of the grooves is always rugged. Thus, the use of rotary wheel-cutting tools could be ruled out. In most cases, the starting points of the strokes are round or flat while the finishing points are always pointed. Moreover, the strokes should be engraved from top to bottom. When vertical or horizontal strokes had been engraved, the shell would be turned about 90 degrees to engrave the crossed strokes from top to bottom. There was no preferred order to engrave vertical or horizontal strokes. Since both sides of the grooves of the characters are neat and there exists no unorganized tool marks, then it is suggested that some sharp tools had been used for engraving characters on the shells. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT Their aim was to examine whether microvascular leakage of endogenous albumin, a representative marker for blood–brain barrier (BBB) damage, was induced in the periventricular area of diabetic db/db mice because periventricular white matter hyperintensity formation in magnetic resonance images was accelerating in elderly patients with diabetes mellitus. Using light and electron microscopes, and semi-quantitative analysis techniques, immunoreactivity of endogenous albumin, indicating vascular permeability, was examined in the periventricular area and spinal cord of db/db mice and db/+m control mice. Greater immunoreactivity of albumin was observed in the vessel wall of the periventricular area of db/db mice than in controls. Additionally, weak immunoreactivity was observed in the spinal cord of both db/db mice and controls. The number of gold particles, indicating immunoreactivity of albumin, in the perivascular area of db/db mice was significantly higher than that of control mice, but there was no significant difference in the number of particles in the spinal cord between db/db mice and controls. These findings suggest that albumin microvascular leakage, or BBB breakdown, is induced in the periventricular area of diabetic mice. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: Interleaved DC-DC converter topologies are gaining popularity for their use as an interface between photovoltaic (PV) source and load. In this paper, a family of coupled inductor (CI) based novel soft switched interleaved DC-DC converter topologies has been proposed to be used for PV application. The topology has been developed from the interleaved stage so as to reduce the input current ripple. The CI stage has been introduced to enhance the power handling capability of the converter. In addition, diode-capacitor multiplier (DCM) cells are connected to obtain higher voltage gain. Since voltage gain extension is obtained through DCM cells and the turns-ratio of the CI, the voltage stress on the main power switches is only a fraction of the output voltage. Further, the diodes present in each DCM cell need to withstand only a low reverse voltage. To enhance the operating power conversion efficiency, the power switches are turned ON under zero voltage switching (ZVS) condition. Experimental results obtained from a 20V-360V, 200W prototype converter validate the operating principle and the advantageous features of the developed topology.

Beschreibung: In order to obtain a high current efficiency a photovoltaic generator PV, it has been necessary to recuperate the heat dissipated by combination a PV to a thermal heating system. The heat exchanger is under the PV, thus cooling the cells back face. Such a system therefore improves the efficiency of the PV module while extracting useful heat calories heating. In this paper, a 3D model of a new PVT collector has been implemented using the Comsol environment. A (FEM) approach is used for the analysis of the thermal and electrical behavior of new absorber integrated for the PVT collector which has as an advantage of a simple realization and to use a material of galvanised steel for it low cost  compared to other configurations of PV/T hybrid collectors. Some results are presented the temperature of the PVT collector decreases with the increasing flow rate, For a flow rate of about 0.0016 kg/s and irradiation of 1000W/m² and ambient temperature equal to 20.15 °C, the temperature reaches a value equal to 55.96°C. The influence of mass flow rate in the PVT collector demonstrate that the PV cell temperature decreases with the increasing mass flow rate and the increases  until the flow rate reaches about 0.0256 m/s; it reaches a value equal to 23.845 °C and electrical power equal to 59.434 after these values will be maintained at a relatively constants values.

Beschreibung: Ecological system is being affected adversely by the use of diesel engines which causes harmful emissions. Alternative sources are being found  to sort out this problem. Biodiesel is one of the alternative source.  Nowadays, there is a focus on the non-edible oils to use it as biodiesel because of its capability to be available on waste lands. Karanja is one of the non-edible oil, which may be  preferred to be used as biodiesel because of its certain advantages on diesel engine comparatively. This experimental study was  aimed to find out performance characteristics and smoke emission with 10%, 20% and 30% biodiesel blend with diesel at varying loads (brake power) of 0.5 to 3.5 kW at a constant speed of 1500 rpm. Brake thermal efficiency, brake specific energy consumption, exhaust gas temperature, mechanical efficiency, volumetric efficiency, air fuel ratio and smoke opacity  of biodiesel blended fuel were evaluated and  compared with diesel and it has been  found satisfactory. Brake thermal efficiency of 20% biodiesel blend fuel was found to be slightly higher  than that of diesel with reduced smoke emissions.  Brake thermal efficiency of B20 and diesel was found to be 29.04% and 29% respectively at 3.5 kW brake power. On the basis of experimental study, the B20 Karanja biodiesel blend is found more useful among all tested fuels in terms of brake thermal efficiency. Smoke opacity was also found to be reduced with Karanja biodiesel blends. Hence Karanja biodiesel is proved to be an environmentally friendly alternative to diesel.

Beschreibung: The partial shading is one of the major problems that exist in the photovoltaic farm installations. This is due to the presence of multi peaks in the power curves characteristics where the conventional methods of maximum power point tracking were not able to solve the problem. To overcome this shortcoming, in the present contribution we suggest a simulator based on a tracker algorithm which is able  to track the global maximum GP in three cases , namely uniform irradiance ,sudden irradiance , and the partial shade conditions. The obtained results are compared to the data reported in the literature and showed good agreement. Thus, our simulator has been extended to include not only uniform irradiance case, but also the other mentioned cases.

Beschreibung: This paper deals with an adaptive maximum power point tracking (MPPT) of photovoltaic systems controlled by a second order sliding mode. The main goal of the proposed work is to track the maximum power point (MPP) using adapted algorithm. In addition, the use of the second order sliding mode control (SOSMC) can reduce the chattering phenomenon and ensure high transient response for a wide range of desired current or voltage under parameter variations. The proposed control is tested under different operating conditions. All results confirm the effectiveness of our proposed algorithm.

Beschreibung: As the power level of a power electronic converter is limited due to several factors and the increase in current causes an increase in stress on switching devices. Besides, the diode reverse recovery current and parasitic resonance current become greater than the main switch can handle, and hence, the size of the boost inductor should be increased to avoid saturation and overheating problems. In order to advance the power level significantly the methods, including device paralleling, module paralleling and interleaving are widely utilized. For some applications, boost stages are designed modularly such that the converter stages can be connected in parallel to meet the increasing power requirement. This method is preferable as it is easy to increase thepower rating by simply stacking converters with increased redundancy. The drawbacks of the method are; it relatively costs high, large volume covered, and cooling difficulties. Furthermore, to provide equal sharing of input current among the converters, additional circuitry should be utilized and the currents of individual converters do not return properly, current of one module can circulate through other module and some unexpected failures may occur. This paper reviews the ripple input current and output voltage of two and three phase and investigates the Performance of four phase IBC.

Beschreibung: One of the prospects for the development of application of gas turbine engines in the decentralized energy system is to use a microturbine units operating on biofuel. Authors in this paper propose a new method of designing of microturbines and consider some aspects and special features in the design of micro-turbines.

Beschreibung: This study involves a performance  analysis between solar photovoltaic (SPV) operated vapour compression and vapour absorption refrigeration systems. For the purpose of comparison, two refrigerators working on different refrigeration cycles (compression and absorption) have been selected. The temperature and energy consumption of both units were recorded by using various parameters. The results show that though the vapour absorption refrigerator takes more time to decrease the temperature of the cabinet in comparison to the vapour compression refrigerator yet it consumes less power. The vapour absorption system is especially useful in rural areas having no or less frequent power supply where we want to preserve drugs and food items because it can maintain a constant low temperature between 6-10°C if delivered on the same temperature . The initial capital cost of the absorption refrigeration system is also less than compression system.

Beschreibung: In this paper, a power control strategy for the brushless doubly fed reluctance generator (BDFRG) based variable-speed wind turbine system is proposed. The proposed control strategy covers all system operational regions including: maximum power point tracking (MPPT) region, constant speed region, and constant power region; whereas, the studies in the literature for the BDFRG wind turbine system are only limited to the MPPT region. For capturing maximum power from the wind in the MPPT region, a turbine power feedback based MPPT, which is a method with fast dynamic response, is used. In the constant speed region, the BDFRG speed is kept constant, and for high wind velocities in constant power region, the controller decreases the BDFRG speed to prevent the increase of the turbine power more than its rated value. In addition, a turbine power observer is proposed to obtain turbine power. The BDFRG wind turbine system model based their dynamic equations, which explained in the paper, is simulated in MATLAB/Simulink software and the performance of the proposed control strategy is studied. The simulation results verify the effectiveness of the proposed control strategy in all three operational regions as well as the acceptable performance of the turbine power observer.

Beschreibung: Inclusion of renewable generation in the existing network is necessary due to the increase in raw material cost for generating electricity and growing demand. Optimal power flow incorporating wind generation is solved using Particle swarm optimization (PSO) in this paper. Weibull distribution function is used for modelling the intermittent nature of wind farm and then it is incorporated in the existing power system network. A direct cost function of the wind power purchased is presented in the paper. Cases without and with wind power are solved using PSO due to its ability in solving the non linear problems. The analysis is carried out on IEEE 30 bus test system and the obtained results are compared with the few existing methods. From the results it can be inferred that this method provides enhanced results.

Beschreibung: The purpose of this study is to develop an all in one and maintenance free power-generating facility for river, ocean or tidal flow. A swivel mile with turbine, power generator, and auxiliary systems are installed in the same axial line and under water level. This architecture can reduce the mechanical loss and increase the efficiency of electric power generation. The facility can be easily lifted up on water level for its maintenance. To realize the all in one architecture, an excellent shaft seal is required. The shaft seal can prevent ingress of water into the facility. The frictional torque of the shaft seal should also be minimized to increase the efficiency of electric power generation. A diameter of the power generator, installed into the facility, should be minimized hydrodynamic resistance from its architecture. Barnacles and algae growth onto the surface of facility reduce the generating efficiency and increase the hydrodynamic resistance. A new technology is adopted from a coating of hydrated material.

Beschreibung: Undoped and Na-doped CuInS 2 powder has been synthetized by direct fusion of precursor elements. We have deposited those two materials in thin films on glass substrate and on copper layer by vaccum thermal evaporation method followed by an annealing in air atmosphere at 250°C and 450°C. We have investigated their structural, optical and electrical properties that show good results for photovoltaic applications. The undoped CuInS 2 layer exhibit an n-type conductivity whereas Na-doped CuInS 2 is p-type both on glass and on copper layer. X-ray analyses of the as deposited samples show amorphous structures. The annealed samples in air showed a crystalized CuInS 2 layer with a major peak of the (112) chalcopyrite phase with the presence of CuO and In 2 S 3 impurity phases for the 450° annealed. Optical gap of both undoped and Na-doped CuInS 2 where between 1.4 and 1.6 eV, that is close to the optimal gap value 1.5 eV of the CuInS 2 suitable for a good absorption of solar spectrum. Electrical characterizations showed good ohmic contacts with low Schottky barrier height, and good ideality factor of respectively (0.75 eV, 1.37) for undoped and (0.66 eV, 1.27) for Na-doped CuInS 2 /Cu contacts. Also, we observed a low value of series resistance 3.51 and 1.75 Ohms respectively that suppose a good current flow in the contact

Beschreibung: Multiphase buck topology offers smaller ripple current and lower component ratings. This, however, compromises unbalanced output current between each phase of an inductor which leads to over-current and inductor saturation issues. Often when discussing the linear control schemes, it involves the use of superposition theorem to understand the system’s response. However, the limitation of superposition theorem in this application is that it assumes the circuit to be completely linear. For components with nonlinear behaviour such as power switches and diodes, the analytical results may not be accurate resulting to unexpected behaviour as the algorithm is implemented on a real system. Hence, the use of a more advanced control scheme is necessary to improve a system with a non-linear characteristic. This paper proposes a current limit control (CLC) consists of MPC for inner loop control and PID for outer loop control for phase current balancing in a four-phase buck converter. The controller is designed to achieve balanced current for each phase with acceptable response time. The proposed system is designed using MATLAB/Simulink simulation software and verified by a laboratory prototype with aTMS320F28335 as the main controller. Simulation and experimental results are provided to validate the system performance.

Beschreibung: Energy management is proposed in order to make a best use of the renewable generation and storage units. The management strategy should guarantee a permanent production of electricity in an isolated chalet for an off-grid system supplied by photovoltaic panels and batteries. The chalet composed by three types of load: priority loads where they will be supplied all time, secondary load where it may be supplied only in case of energy availability and finally the extra-loads will be supplied during a definite time. This paper presents a model for isolated system behavior in terms of control powers exchanged between sources power and loads demand. The model is based on Timed Hybrid Petri Net formalism. Therefore, an iterative algorithm for power flow management satisfies requirement of each type of load based on the photovoltaic panels production and the storage units. Obtained results show that the proposed strategy satisfies the priority loads during the whole day, covers the secondary load energy and gives user liberty to exploit the extra-loads as possible.

Beschreibung: The aim of this paper is to propose a neural network based reference modified PID control which has a simple duration design method for transient characteristics improvement of digitally controlled dc-dc converters. In renewable energy network systems, various types of dc-dc converters are widely used for power conversion and such converters require a superior control method for a stable operation. Especially, transient characteristics should be improved since they heavily affect the stability of the system. For such purposes, designing of conventional control methods becomes a difficult task since the optimization of control parameters needs complicated analysis and it is affected from variations of circuit components of converters. Therefore, simple and easy design of control is widely required for a stable operation of power converters. The neural network can provide a suitable control methodology for such situation since it treats the plant as a black box and it can realize a non-linear control based on training of the input-output relation without complicated modelling and analysis. On the other hand, the neural network based method has a disadvantage caused from the fact that the neural network is trained with data obtained in advance and an overcompensation phenomenon occurs in the transient response. In this paper, the neural network control is adopted to control the dc-dc converter in coordination with a conventional PID control. The neural network predicts the output voltage of the converter and the reference value in the PID control is modified with the predictions to reduce the error of the output voltage. To avoid overcompensation, a simple duration design for the neural network control is also provided to improve the transient response effectively. From prototype testing in simulation and experiment, it is revealed that the proposed method contributes to obtain a superior transient performance compared with the conventional PID control.

Beschreibung: The penetration of wind generation in modern day energy system is increasing day by day. Wind is a variable parameter in nature which has a significant effect on the generator behavior. Since most of the existing installed generators are self-excited induction generators (SEIG), they have a negative effect on the system during varying wind speeds and varying load. The primary parameter found responsible is reactive power requirement for self-excitation. So, instead of replacing these generator sets, an alternative reactive power source connected in coordination to machine can well handle these situations. In this context a new promising method of stabilizing SEIG with doubly fed generator (DFIG) is developed in this paper. A new technique of representing DFIG in terms of its equivalent capacitance is developed, to study reactive its power handling capabilities. The potential of the developed model in stabilizing the SEIG during varying wind speeds and varying load conditions is simulated and analyzed. The developed model is independent of complex d-q axis model and simple to understand the behavior of machine. The result shows that this method of supplying reactive power requirement of SEIG is satisfactory in maintaining voltage build up of SEIG. The results obtained are well validated by power balance.

Beschreibung: This paper aims the integrationof photo voltaic array and battery in a micro grid and management of energy happening in the grid. The regulation of battery depending on the requisite of load i.e., battery hold, charge and discharge actions using a bi-directional DC-DC converter has been proposed. The usage of a simple boost converter and interleaved boost converter with MPPT control, two-level inverter and three-level NPC inverter has been compared for various situations like PV delivering supply to the load and charging battery, only PV system delivering supply to the load, only battery delivering supply to the load and PV-battery both delivering supply to  the load. Output factors like power, voltage and current are analyzed and plotted for all the situations. The proposed micro grid energy management system is simulated under MATLAB/Simulink environment

Beschreibung: A dye sensitized solar cell (DSSC) was fabricated using nanoporous TiO 2  film and dye extracted from Kenaf Hibiscus (Hibiscus Cannabinus) flower. To the best of our knowledge, dye extracted from kenaf hibiscus has not been used as photosensitizer for DSSC application till date. The TiO 2­  film was fabricated on ITO coated glass and further absorbed in  dye which acted as photo anode and another ITO coated glass with a platinum coating was served as counter electrode (cathode). An optimal blend of acetonitrile (solvent) (50-100%), 1,3-dimethylimidazolium iodide (10-25%), iodine (2.5-10%) and lithium iodide, pyridine derivative and thiocyanate was used as electrolytes in the DSSC. The different structural, optical and electrical characteristics were measured. The DSSC showed a maximum conversion efficiency of 2.87 %.

Beschreibung: Rotary machines have many rotating structures necessity design-optimization. Their structure motions are controlled at low-frequency by rigidity, at high-frequency by inertia and at-resonance level by damping. Using modal model, dynamic design of the structure developed can be predicted, analyzed and improved. Recently, H-Darrieus wind turbine has (HDWT) received considerable attention due to its inherent structural characteristics. This machine intends a promising design of renewable energy conversion system in urban areas and isolates sites. Though, the system suffers of several dynamic problems caused by geometry, centrifugal and aerodynamic cyclic loadings. Present paper investigated dynamic design-optimization of a three-bladed (HDWT) based on its natural structural parameters using 3D CAD, FEA using SolidWorks modeling and simulation. From simulation result obtained, the first five natural frequencies of the system, corresponding mass participate, damping factor, and mode shapes are predicted and analyzed. The static and dynamic stability and reliability of the system are shown since security factor and all quality indicators  tested, amplification factors, and resonant amplitude ratios are consistent according to the recommendations of structure dynamics standards. Furthermore, critical operating conditions of wind turbine under forcing excitations of the wind speeds at various regimes are also treated and assessed.

Beschreibung: Dye sensitized solar cells (DSSCs) based on natural dyes extracted from dried Hibiscus Sabdariffa and Rosa Damascena flowers were fabricated. The extracts were characterized by UV-Vis absorption spectroscopy. The TiO 2 nanopowder paste was spread on FTO layers to form a thin layer. Three processes were conducted to improve the cell efficiency such as pre- and post-treatments of TiO 2 and FTO layers with three acids and changing the pH of the extract solutions. The conversion efficiency of the DSSCs sensitized with Hibiscus Sabdariffa enhanced by 107% and 114% when treating the FTO sheets for 5 min with H 3 PO 4 and HCl, respectively. It was observed that when HCl acid was used to adjust the pH value of the dye solution of Rosa Damascena to 2.0, the efficiency of the DSSC was enhanced by about 180%.

Beschreibung: Global environmental concerns and gradual escalation of fuel cost linked with conventional energy sources encouraged the use of renewable energy in electric power supply sector greatly. India is blessed with great environmental wealth of solar energy due to its favorable location (40ºS to 40ºN). This research work explores the viability of great solar potential of 14 Indian geographical locations by estimating Global Solar Radiation(GSR) for four summer months using Artificial Neural Network (ANN). Initially, eight parameters are chosen as input data set for ANN from a number of environmental factors influencing GSR,based on their natural dependence on it. But, less correlated inputs as training data set for ANN results lead to more sensitive outputs.So, lately, inputs to the ANN are extracted based on Spearman rank-correlation coefficient, where only positively correlated input factors are considered as the input data set for the ANN to enhance its performance.Spearman rank-correlation coefficient describes the extent of correlation between two variables using a monotonic function by utilizing rank-order of the data regardless of distribution between two data sets.  This makes it suitable not only for discrete and continuous variables but also ordinal variables (data sets including inconsistent values).A multi layered, feed forward, standard ANN model with one hidden layer and five hidden neurons corresponding to least mean square error is considered among various ANN models with different training algorithms, hidden layers and neurons, for the prediction of GSR. It is found that correlation based ANN predominatessimple ANN.

Beschreibung: The determination of the value of investment projects must take into account the risk-return trade-off present in the market. The fiscal, economic and monetary policies of the various international organizations have an impact upon the market and subsequently on the perception of risk. This study analyses the trend of one of the parameters for risk assessment in valuation processes, between 2011 to 2013, for the specific sector of small and medium-sized enterprises involved in generating electrical energy from alternative sources in Spain

Beschreibung: This paper develops an efficient solution towards the prognostics of industrial PEMFC. It involves employment of an efficient multi-energetic model suited for diagnostics and prognostics, developed in Bond Graph framework. The Electrical-Electrochemical (EE) part constitutes the main focus for the problem of prognostics, wherein deviation of the global resistance and limiting current inspires a statistical linear degradation model (DM), under constant current load conditions. The benefits of Particle Filters (PF) is integrated with the BG model derived Analytical Redundancy Relations (ARRs), for prognostics of the electrical-electrochemical (EE) part. The prognostic problem is formulated as the joint state-parameter estimation problem in Particle Filter framework. Using PF algorithms, in probabilistic terms,  estimation of State of Health (SOH) is obtained along with the estimation of the associated parameter that influences the rate of degradation. A simplified variance adaptation scheme is employed to ameliorate the accuracy of remaining useful life (RUL) predictions.  Influence of variance adaptation on SOH estimation as well as RUL prediction is assessed.  It is shown that a proportional type of variance control leads to better accuracy in RUL predictions accompanied with precise confidence bounds. As the degradation data is obtained from a real industrial PEMFC, the economic viability of this approach for prognostics of PEMFC is significantly high.

Beschreibung: In recent years, the renewable energy system requires the modeling language based control and the high-performance CPU. As for CPU, the improvement of the CPU performance reaches its limitation caused from its clock frequency. Therefore, the multi-core and the virtualization are mainstream strategies for its improvement and such mechanisms have some issues including complicated algorithm of controller and inheritance of design on CPU architecture generation. For such reasons, Field Programmable Gate Array (FPGA) is expected to replace the role of CPU since it has several advantages such as long period supply, inheritance and power-saving. It is applied to the small machinery control so far, and there are few researches to apply it to the power plant control. For such purpose, a flexible control with the modeling language like CPU and on-line modification of the control logics are necessary. In this paper, to fulfill such requirements on the control system for the infrastructure like the power system, a new FPGA based controller named "green controller" is proposed. An architecture to realize it and required conditions based on FPGA are clarified. Furthermore, performance and FPGA resource usage are measured in the experiment with the proposed architecture for evaluation.

Beschreibung: An advanced modulation technique-based harmonic control approach, known as hysteresis inverter control, in an inverter-connected renewable energy source (RES)-based islanded microgrid system is proposed in this paper. An LC low-pass filter is also used with the feedback control scheme in order to ascertain the control of harmonics in a desired manner. With a view to understanding both the fundamental and harmonic components of the output wave-shapes, fast fourier transform (FFT) analysis is carried out in this paper. MATLAB software is used to simulate the inverter performance within a microgrid system with the proposed feedback control. It has been found that system wave-shapes are sinusoidal and the total harmonic distortion (THD) is less than 0.5%, meaning the proposed method is effective.

Beschreibung: The country's industrial development has led to increment in consumption of energy. Thus, energy saving is substantial in developed countries. Due to implement of cement in industry construction, authentic manufacturing method is essential. Cement is considered as high consumed source for industry which requires high productivity. On the other hand, imminent depletion of fossil resources, leads to utilization of alternative fuels. In this paper, we explore the possibility of alternative refuse-derived fuel (RDF) from Rasht city for Lowshan Cement Factory. The best choice of RDF for Lowshan cement factory is Fluff RDF. Considering the amount and the type of waste, 168 tons per day Fluff RDF has been calculated. It was determined that the use of RDF as an alternative fuel could raise heating value and lower production costs. 168 tons of RDF with heating value of 17790Kj/kg would be 21.2% of the energy needed to supply the cement factory. Exergy efficiency of the reaction is increased by applying RDF. By increasing the amount of paper in RDF, exergy efficiency increment rate is more than other material contained in RDF.

Beschreibung: The increasing cost of energy associated with higher production of polluting gases is a major threat to the whole world. It is a high time to find out alternative pollution free energy resources. Fuel cell is one such electrochemical energy producing unit to produce clean electrical energy. The major challenge in the development of fuel cell is to produce inexpensive, high energetic electro catalytic electrode materials. Present investigation deals with electrochemical characterization of the synthesized Ni-Co-Fe, MnO 2 -C, ZnO-Al 2 O 3 and Ni-CeO 2 -Cu for electrochemical oxidation of fuels like methanol, ethanol, and glucose. It has been found through studies of Polarization test, Cyclic Voltammetry, Chronoamperometry that all these electrodes performed very well with low polarization resistance, high exchange current density and delivers maximum current from the fuel oxidation. But the electrode Ni-CeO 2 has outperformed all other materials including Pt. The electro-synthesis of these materials has been performed at an optimum current density, potential, electrolyte chemistry by a series of experiments. The materials were characterized by XRD which confirms the constituent’s presence of metals and metal oxides. The SEM studies exhibits grain refinement of Ni-CeO 2 due to CeO 2 addition. The fact confirms the fine grain 3D structure account for fast electrochemical reaction of the fuel.

Beschreibung: ABSTRACT Alzheimer's disease (AD) is the main cause of dementia in the elderly population. Over 30 million people worldwide are living with dementia and AD prevalence is projected to increase dramatically in the next two decades. In terms of neuropathology, AD is characterized by two major cerebral hallmarks: extracellular β-amyloid (Aβ) plaques and intracellular Tau inclusions, which start accumulating in the brain 15-20 years before the onset of symptoms. Within this context, the scientific community worldwide is undertaking a wide research effort to detect AD pathology at its earliest, before symptoms appear. Neuroimaging of Aβ by positron emission tomography (PET) is clinically available and is a promising modality for early detection of Aβ pathology and AD diagnosis. Substantive efforts are ongoing to develop advanced imaging techniques for early detection of Tau pathology. Here, we will briefly describe the key features of Tau pathology and its heterogeneity across various neurodegenerative diseases bearing cerebral Tau inclusions (i.e., tauopathies). We will outline the current status of research on Tau-specific PET tracers and their clinical development. Finally, we will discuss the potential application of novel super-resolution and label-free techniques for investigating Tau pathology at the experimental level and their potential application for AD diagnosis. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT This review reports on the combined use of the atomic force microscopy (AFM) and several type of optical/fluorescence/laser scanning microscopy for investigating cells. It is shown that the hybrid systems of AFM with optical-derived microscopies enable to study in detail cell surface properties (such as topography), their mechanical properties (e.g., Young's modulus) mechanotransduction phenomena and allow to gain insight into biological-related pathways and mechanisms in the complex nanoworld of cells. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: The performance of a four stroke, single cylinder, direct injection CI engine is evaluated having fuel as neat jatropha-diesel blend in proportion 2:1 on a volume basis. The experimentations were conducted to test engine performance and emission characteristics at throttle settings of 25%, 50%, 75% and 100% and variable loads covering under load to overloading of engine operation. The effect of jatropha blend on engine brake power, brake thermal efficiency and specific fuel consumption were observed at different loads and throttle openings along with exhaust emissions and exhaust gas temperatures. Compared to jatropha blend diesel provides better performance for entire operating range (of loads and throttle openings) but effect of varying load /throttle settings on performance characteristics are of similar nature. The jatropha blend produces lower hydrocarbon and NO x emission, highlights the positive aspects of combustion and the allowance of higher effective compression ratio of the blend.

Beschreibung: In this paper are presented experimental results obtained by equipping vertical axis wind turbine with electric generator. In the experiments were tested two ways of equipping the turbines, first with a generator connected directly to the rotor shaft and second with a generator, with less power, connected to the rotor shaft through a toothed wheel gear. To achieve these tests were used three types of vertical axis wind turbines, i.e. a single stage Savonius rotor, a double stage Savonius rotor and a single stage type ‘Z’ Savonius rotor.  After tests it was observed that the best solution for equipping wind turbines with electric generator is the one with the connection to the rotor shaft through a toothed wheel gear. In this case, even if the rotor speed values are closer to the first case, the voltage is much higher. At wind speed of 3 and 4 m/s, the single stage Savonius rotor generates more power than the other two. At wind speed of 5 m/s, the greatest amount of power was generated with the double stage Savonius rotor. Following these tests, it can be concluded that, in order to ensure the highest energy production, is recommended to use vertical axis wind turbine with double stage

Beschreibung: With more than 4000 hours/year sunshine duration, Algeria is blessed by a perfect geographic location which makes it suitable for solar domain applied studies as solution for the future of the green renewable energies. Unfortunately, despite the great support given by the state and mines minister to encourage the Algerian population to integrate solar energy especially for the southern regions, The survey shows that people hesitates the integration of this type of sources looking the increases of the prices for these systems; mainly the storage part using batteries cell storage. Even the new technology based on lithium ion batteries that gives more storage capacity and more performances; remains out of reach for the majority of citizens which is the case in the different parts of the world. With collaboration between LGEC laboratories within a full support from the ministry of mines under a Basic deliver although precise data by CDER (National Center for renewable energies) and URAER (the applied research unit for renewable energies). Through this article, the researchers propose a thorough study of a whole solar pumped hydro energy storage plant system for a consumption model on the wilaya of Ghardaia in the southern of Algeria.

Beschreibung: In this paper, we have studied and analyzed the shading effect on solar photo voltaic (SPV) modules connected in series using four 75 W SPV modules for three different shading conditions: (1) one module is fully shaded, (2) two modules are fully shaded and (3) three modules are fully shaded. The performance of the modules which decreased due to shading effect are improved in each case using bypass diodes connected in parallel with each of the modules. This analysis is done by using the simulation model in PSCAD and an outdoor experiment is also performed to validate the simulation results for the same configurations. An improvement in open circuit voltage (V oc ), short circuit current (I sc ), maximum power (P max ) and power efficiency are observed when bypass diodes are used. During an outdoor experiment when one panel is shaded the power efficiencies are 17.96 % and 12.79 % with and without bypass diodes respectively. In case of two modules are shaded these values are 14.50 % and 9.63 % respectively. When three modules are shaded the power efficiency is 3.59 % in case of without bypass diode, which is increased to 6.87 % with bypass diodes.

Beschreibung: The Greenhouse gas (GHG) emissions turns out to be one of the most important factor contributing to global warming significantly. Literature revealed that reservoirs too can be an important source of emissions, especially in tropical areas. A lot of efforts have undergone in determining the GHG from reservoirs, however, due to various uncertainties like lack of standardized measurement tools and techniques, till date the determination has been little difficult. Some of the international organization like United Nations Educational, Scientific, and Cultural Organization (UNESCO), International Energy Agency (IHA), and International Hydropower Association (IEA) has been making a lot of effort to know the contribution that reservoirs make in GHG emissions. The key objective of this paper is to find policy and challenges at different scales that could help to address the GHG emissions from reservoirs and its impact on climate change. 

Beschreibung: Performance and emission characteristics of diesel engine were reviewed in this work. This study was conducted by revising works that were conceded out using biodiesel prepared from the raw oils of: palm, moringa, Jatropha and diesel fuel. In this review study we consider only 20% of each biodiesel (described as MB 20 , PB 20 , and JB 20 ) was tested in diesel engine, given that open literature indicates the possible use of biodiesel of up to 20% in a diesel engine without any engine modification. All biodiesel fuel samples reduce brake power (BP) and increase brake specific fuel consumption (BSFC) than diesel. Diesel engine emission results indicated that blended fuel reduces the average carbon monoxide (CO) and hydrocarbons (HC) emissions except nitric oxides (NO x ) emissions than diesel fuel. B 20 blend of biodiesel is a suitable source for alternative fuel, with ecological welfares. Among the biodiesel blended fuel, Palm biodiesel showed better performance and minimum emission than jatropha and moringa biodiesel fuel. Although PB 20 showed better performance, but performance of MB 20 biodiesel blend is comparable with other fuels. Correspondingly, MB 20 can be used in a diesel engine without any engine modification.

Beschreibung: – Many modifications have been made on c onventional Savonius wind turbine’s rotor blades have been made to improve the performances. The rotor blade modification in this research is a blade combination where the circle-shaped conventional model is combined with the one of a concave elliptical model. The combined blade will not affect the simplicity of construction and cost of manufacture of turbine rotors.  The aim is to analyze the influence of the blade combination towards the performance of Savonius turbine. The research includes experimental method using open-jet-type wind tunnel of rotor’s prototype with three different blade models of the same dimension. The experiment shows, there are influences of the modification of the rotor blade to the performances of the turbine. The combined blade improves the performances of the power coefficient maximum (Cp max ) up to 11 % compared to the conventional blade at the tip speed ratio (TSR) of 0.79 Keywords - Savonius turbine, combined blade, experimental, performance

Beschreibung: This paper presents modeling and control of Photovoltaic/fuel cell/supercapacitor hybrid power system for stand-alone applications. The hybrid power system uses solar PV array and fuel cell as the main sources. These sources share their power effectively to meet the load demand. The supercapacitor bank is used to supply or absorb load transients. The main control system comprises of MPPT controller for PV system, a DC-DC boost converter with controller for fuel cell system for power management and inverter controller to regulate voltage and frequency. The stand-alone hybrid system aims to provide quality supply to consumers with a constant voltage and frequency. The modeling and control strategies of the hybrid system are realized in Matlab/Simulink.

Beschreibung: ABSTRACT The study of phenotypic variation in plant pathogenesis provides fundamental information about the nature of disease resistance. Cellular mechanisms that alter pathogenesis can be elucidated with confocal microscopy; however, systematic phenotyping platforms—from sample processing to image analysis—to investigate this do not exist. We have developed a platform for 3D phenotyping of cellular features underlying variation in disease development by fluorescence-specific resolution of host and pathogen interactions across time (4D). A confocal microscopy phenotyping platform compatible with different maize–fungal pathosystems (fungi: Setosphaeria turcica , Cochliobolus heterostrophus , and Cercospora zeae-maydis ) was developed. Protocols and techniques were standardized for sample fixation, optical clearing, species-specific combinatorial fluorescence staining, multisample imaging, and image processing for investigation at the macroscale. The sample preparation methods presented here overcome challenges to fluorescence imaging such as specimen thickness and topography as well as physiological characteristics of the samples such as tissue autofluorescence and presence of cuticle. The resulting imaging techniques provide interesting qualitative and quantitative information not possible with conventional light or electron 2D imaging. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: Nanotechnology plays a major role in heat transfer related problems. This study evaluates the effect of nanofluid as a working fluid on parabolic solar collector’s overall efficiency through both experimental and CFD analysis. α-Al 2 O 3 nanoparticle of 20 nm average size is used for the preparation of  Al 2 O 3 -H 2 O (DI)  nanofluid of four different volumetric concentrations of 0.05%, 0.75%, 0.1% and 0.125% respectively. Working fluid is made to flow at three different volume flow rates (30 LPH, 50 LPH and 80 LPH). ANSYS FLUENT 14.5 is used for carrying out CFD simulation, where solar flux is modelled through solar load cell and solar ray tracing. It has been observed that, there is improvement in instantaneous efficiency, thermal efficiency and in overall efficiency, when water is replaced by Al 2 O 3 -H 2 O (DI) nanofluid and also with corresponding increase in the mass flow rate of working fluid. An improvement of about 9.31%, 11.87%, and 13.98% in the collector’s overall efficiency is seen, when water is replaced by 0.125% vol. conc. Al 2 O 3 -H 2 O (DI) nanofluid at a flow rates of 30 LPH, 50 LPH and 80 LPH respectively. Also, both experimental and CFD analysis results are in close agreement with a difference of 8%.

Beschreibung: Bangladesh is one of the largest populated countries of the world, where more than one third of the population is living without electricity. Being a developing country, the demand of electricity is increasing tremendously.  Meanwhile, fossil fuel based electricity generation plants are lagging behind to supply the rising demand and the fossil fuel sources are very limited. As an alternative, renewable energy based systems are becoming popular in Bangladesh, particularly solar, wind and hydro based systems, which are being set up in different sizes and configurations. This paper presents feasibility analysis of renewable energy based hybrid system for the village of Kuakata, in the southern area of Bangladesh. The system is designed based on the resources available at the location. The sources considered in the analysis are solar PV, wind, diesel generator and battery backup system. HOMER simulation model has been developed for simulating the system with real weather data and nominal load profile. The cost of the system is determined based on the real market price of the components. Sensitivity analysis has also been carried out on the best suitable system to prove the system sustainability in the future. For sensitivity analysis, the change in load and change in rate of interest has been considered. Based on the factors such as initial cost, replacement cost, operating cost, total net present cost (TNPC), cost of energy (COE) and exhaust gas emission, the results show that PV-Wind-Battery based system is a feasible solution for the situation. The optimum system has the initial cost of 126,586 $, replacement cost of $ 125,280, operating cost of 5007 $/year, TNPC of 224,345 $ and COE of 0.161 $/kWh with no exhaust gas emission. Foremost, the emission is zero, which means it is green energy system.

Beschreibung: The aim of the paper is to enhance the performance of membrane supported water desalination techniques to reduce the consumption of energy by employing solar energy. Development of the pilot plant in the laboratory has been carried out to desalinate the brackish water using PV collector. Experimental study was carried out and report the effect of temperature, time and flow rate on permeates flux. Results show that permeates flux increases with increase in temperature. Also the analysis of the well water has been performed by various techniques and reported. It was found that vacuum membrane distillation using solar energy provide better quality of water in comparison to other treatment techniques. This study provides an idea for the application of renewable energy in the field of desalination of water on a small scale.

Beschreibung: Global warming has become a threat of our time. It poses challenges to the existence of all biota on this earth and has made a clear impact on the level of energy and water consumption. No doubt, increase in the ambient temperature increases indoor and outdoor temperature level of the buildings which catalyzes the use of energy and cost intensive mechanical air-conditioning systems. Green roof tops belong to such an idea for cutting down the energy consumption and enhancing the comfort level of commercial and residential buildings. This paper investigated the impact of green roof on thermal performance and cooling potential in Indian climate.  It was observed experimentally that compared to the exposed roof, the room air and interior surface temperature of the green roof were reduced by a maximum of 17% and 22% respectively. Heat flux studies show that not only the peaks are lower but also the diurnal heat fluctuation through the green roof assembly is lower than that of the conventional roof in the case of heat in-leak. Further, a thermal lag of around 2 to 3 hours has been observed. The simulated model developed in this study has been closely replicated by the experimental data, thereby efficacy of the model is demonstrated unequivocally.

Beschreibung: The emergence of the Distributed Generation (DG) units along with their application in the distribution system level has led to the establishment of microgrids. microgrids are a part of the distribution network in which, in addition to the loads, there are microsources operating in two modes, i.e. grid-connected mode and island AKA standalone mode. In the grid-connected mode, the load is supplied through local DG units, and if necessary, power is exchanged with the upstream grid, concerned as well.  Considering the development of DG units technology in recent years which in turn, has led to the expansion of microgrid concept  , microgrid planning meaning determining the capacities of local DG units assumes an extraordinary significance, taking the technical, economic and environmental considerations into account. This research tries to study the optimized planning for a grid-connected hybrid microgrid. The case study was conducted in Razi University in Kermanshah, Iran. Due to the stochastic behavior of renewable energies based DG units, the uncertainties about the amount of generated power from these resources are considered using appropriate probability density functions. The problem is a Mixed Integer Non-linear Program (MINLP), to be solved by means of GAMS software. In order to bring about optimized results, microgrid simulation is processed in assorted scenarios, both in probabilistic and deterministic modes. In the end, the results are compared to those resulted from Homer Energy software. 

Beschreibung: Maximum Power Point Tracking (MPPT) techniques are most famous application in photovoltaic system to track the maximum power of the PV system. Usually, most of maximum power point tracking algorithms used fixed step and two variables: the photovoltaic (PV) array voltage (V) and current (I). Therefore both PV array current and voltage have to be measured.   The maximum power point trackers that based on single variable (I or V) have a great attention due to their simplicity and ease in implementation, compared to other tracking techniques. With traditional perturb and observe algorithm based on two variable (I and V)  using fixed iteration step-size, it is impossible to satisfy both performance requirements of fast response speed and high accuracy during the steady state at the same time. To overcome these limitations a new algorithm based on single variable method with variable step size has been investigated which has been implemented using fuzzy logic control.  The proposed method has been evaluated by simulation using MATLAB under different atmospheric conditions. The obtained results show the effectiveness of the proposed technique and its ability for practical and efficient tracking of maximum power.

Beschreibung: As the penetration level of wind energy in power system increases, stable operation of power system would get impacted by wind turbine's characteristics. The stability issue derived from this fact that the squirrel cage induction generators (SCIG) used in these turbines potentially would cause voltage drop and voltage stability problems in network, regarding to its reactive power absorption tendency. Thus, detection of effective parameters in increment and reduction of unstability occurrence probability could make SCIG based wind farm predictable and eventually cause improvement in voltage stability margin of whole of power system. In this paper, effective factors of wind farm operation connected to the network are assessed and studied in two sections. The first section includes parameters which depend upon substantive and functional characteristics of induction generator and could threat the stability of power system. The second section containing such parameters and characteristics of power system as which are able to affect the stable operation of SCIGs and can be lead to instability in whole of the power system. Eventually reactive power has been identified as more effective option in system designing. The studies are concentrated on voltage stability and small signal stability. In order to make the results more practical, the 660KW inductive generator which is widely used in Iran is studied in this paper.

Beschreibung: - A project is undertaken by the College of Engineering Bhubaneswar, Odisha, India to design and develop a biogas production, purification, compression and storage system suitable for the use as a cooking gas in rural households. The biogas is produced in a floating drum type digester by the anaerobic digestion of kitchen wastes. The design is the foot lever compressor which allows the users to stand and compress using foot lever and a valve system, which will allow for variable work input for compression. The final prototype is able to compress the biogas to approximately 4bar in a 0.5m3 tank. In addition to the compressor, there is also a fibre container with steel wool to act as a hydrogen sulfide scrubber in-line with the inlet of the biogas to the compression system. The result showed that the system could compress biogas into a container, 4 bar pressure and operating time of 30 min. 

Beschreibung: This study presents techno-economical analysis of grid connected photovoltaic system for powering the Madan Mohan Malaviya University of Technology, Gorakhpur situated at Northern sub-region of India. Load data of university is taken from the Substation and solar data is taken from solar resource setup at the university. The system is optimized for the load and solar data by the HOMER software. Different rating of photovoltaic panel and inverters are studded in the search space. The best feasible system is chosen according to net present cost of the system and carbon dioxide reduction. From the results, it is found that 500kW PV panel and 500kW inverter is the optimal solution for university. This system has 37% renewable fraction and cost of electricity is just about $0.1/kWh. This system will reduce the emission of CO 2 gas about 544 tones in a year.

Beschreibung: Among renewable sources, wind source is the more sympathetic and favorable source because it is free from pollution and no carbon die emissions as it appraised in conventional energy sources. Based on existing literature, the development of wind-generator dynamic model is of great interest nowadays. In this paper, a complete dynamic wind-generator mathematically modeling approaches for wind energy system is carried out. Moreover, due to uncertain wind speed circumstances, it is desirable to evaluate the state of the art stability and controller performance analysis for wind-generator unit through feedback control techniques based on field oriented control concept, which plays a significant role in power system stability and control. The proposed dynamic wind-generator system model consists of three phase cage rotor induction machine unit, and it is intended in Matlab software tool for the simulation purpose. The dynamic wind-generator system stability and control design has broadened prospectus for the applications and developments.   Among renewable sources, wind source is the more sympathetic and favorable source because it is free from pollution and no carbon die emissions as it appraised in conventional energy sources. Based on existing literature, the development of wind-generator dynamic model is of great interest nowadays. In this paper, a complete dynamic wind-generator mathematically modeling approaches for wind energy system is carried out. Moreover, due to uncertain wind speed circumstances, it is desirable to evaluate the state of the art stability and controller performance analysis for wind-generator unit through feedback control techniques based on field oriented control concept, which plays a significant role in power system stability and control. The proposed dynamic wind-generator system model consists of three phase cage rotor induction machine unit, and it is intended in Matlab software tool for the simulation purpose. The dynamic wind-generator system stability and control design has broadened prospectus for the applications and developments.

Beschreibung: ABSTRACT The description and application of a modified Scanning Electron Microscope preparation technique using hexamethyldisilazane for small parasitic copepods was demonstrated though a high resolution depiction of individuals of Ergasilus labracis sampled from three spined stickleback ( Gasterosteus aculeatus) in Bay D'Espoir, Newfoundland during summer 2015 and from archival samples retrieved from Atlantic salmon par ( Salmo salar ) stored at the Atlantic reference centre, St. Andrews, New Brunswick. The specimens were very well preserved showing high quality detail of important features and verifying those previously described using light microscopy by Hogans. Additionally the technique allowed excellent in situ demonstrations of mouth parts, swimming legs, and unusual and previously undescribed features of the second antenna including prominent striations and pore-like structures found to define the claw. It is thought that this technique will become a quick and efficient tool for describing important taxonomic features of small parasitic copepods like E. labracis or other similar small aquatic organisms. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT The endometrial layer of the uterus is characterized by continuous cycle of cell growth and apoptosis in response to hormonal changes. Apoptosis is regulated by several apoptotic regulators, but their significance in involuting uterus has not been well understood. For that reason, aim of this study was to investigate possible role of apoptosis-related proteins (bax and survivin) and enzymes (caspase-3 and calpain-1) in the involuting uterus of the rat, using immunohistochemistry. Our results indicated cytoplasmic and nuclear immunostaining for bax, caspase-3, calpain-1 and survivin proteins were found in the endometrial epithelium and stromal cells such as fibroblasts, mast cells and macrophages, and blood vessels; however, calpain-1 immunoreactivity in the endometrial fibroblast was quite weak or absent. Supranuclear punctate bax immunolabelling was also observed in the endometrial fibroblasts and luminal and glandular epithelial cells from days 1st and 3rd following parturition, respectively. Although survivin was localized in the apical cytoplasm underneath the apical membrane of the luminal epithelium on the 1st and 3rd days, it was also localized in the apicolateral membrane and basal cytoplasm on the 10th and 15th days of involution. Immunostainigs demonstrated that expression patterns of all examined proteins varied with structural changes in the luminal epithelium, and number of immunopositive fibroblasts for bax, caspase-3 and survivin increased with advance of postpartum days and reached a maximum on postpartum days 10 and 15. These results suggest that the process of postpartum involution of endometrium may be regulated by apoptotic and non-apoptotic activity of bax, caspase-3, calpain-1, and survivin. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: A large scale isolation and purification of theaflavin (TF) and epigallocatechin (EGC) has been successfully developed by tannase-mediated biotransformation combining high-speed countercurrent chromatography. After tannase hydrolysis of a commercially available theaflavins extract (TE), the content of TF and EGC in tannase-mediated biotransformation product (TBP) achieved approximately 3 times enrichment. SEM studies revealed smooth tannase biotransformation and the possibility of recovery of the tannase. A single 1.5 hours' HSCCC separation for TF and EGC employing a two-phase solvent system could simultaneously produce 180.8 mg of 97.3% purity TF and 87.5 mg of 97.3% purity EGC. However, a preparative HPLC separation of maximum injection volume containing 120 mg TBP prepared 11.2 mg TF of 94.9% purity and 7.7 mg EGC of 89.9% purity. HSCCC separation demonstrated significant advantages over Prep HPLC in terms of sample loading size, separation time, environmental friendly solvent systems, and the production.

Beschreibung: Acute lymphoblastic leukemia (ALL) is a cancer that starts from the early version of white blood cells called lymphocytes in the bone marrow. It can spread to different parts of the body rapidly and if not treated, would probably be deadly within a couple of months. Leukemia cells are categorized into three types of L1, L2, and L3. The cancer is detected through screening of blood and bone marrow smears by pathologists. But manual examination of blood samples is a time-consuming and boring procedure as well as limited by human error risks. So to overcome these limitations a computer-aided detection system, capable of discriminating cancer from noncancer cases and identifying the cancerous cell subtypes, seems to be necessary. In this article an automatic detection method is proposed; first cell nucleus is segmented by fuzzy c-means clustering algorithm. Then a rich set of features including geometric, first- and second-order statistical features are obtained from the nucleus. A principal component analysis is used to reduce feature matrix dimensionality. Finally, an ensemble of SVM classifiers with different kernels and parameters is applied to classify cells into four groups, that is noncancerous, L1, L2, and L3. Results show that the proposed method can be used as an assistive diagnostic tool in laboratories.

Beschreibung: Perpendicular or parallel magnetic fields are used to magnetize the tips used in magnetic force microscopy (MFM). In this process, perpendicular or parallel magnetic dipole moments are produced on the tip plane, thus leading to the formation of polar magnetized tips (PM-tips) or longitudinally magnetized tips (LM-tips), respectively. The resolution of an MFM image of a magneto-optic disk is used for calibration of these tips, and the saturated magnetic fields of the PM- and LM-tips are found to be 2720 Oe and 680 Oe, respectively. Because both tips can simultaneously magnetize the sample during the scanning process when measuring a Co thin film, clear MFM images are captured, which enable the identification of magnetizable regions and the distribution of the magnetic domains on the sample surface. These results will be useful for improving the manufacturing processes required for soft nano-magnetic film production.

Beschreibung: Objectives The aim of this study was to create an analytical tool for the three-dimensional distribution of immunohistochemically stained cells in the arteriovenous (AV) loop model of the femoral vessels of rats that fuses two-dimensional histological slides into stacks. Methods: A total of 22 AV loops were implanted into male syngeneic Lewis rats by creating an arteriovenous fistula between the femoral artery and vein by interposing a femoral vein graft of the contralateral extremity. This fistula was embedded into an isolation chamber filled with a fibrin matrix. Specimens were explanted after 7 to 14 days, and the AV loop was processed using standard histological protocols. Immunohistochemical staining for HIF-1α and a counter staining with hematoxylin was performed. Various layouts with different cutting planes, regions of interest, and post-processing algorithms were evaluated. Results and observations: The proximal-to-distal cutting perpendicular to the vascular axis proved to be the best layout for mapping the three-dimensional constructs containing the AV loop. A semi-automatic algorithm for the differentiation of immunohistochemical positive and negative cells was developed. Conclusion: The newly established methods from this study constitute an excellent tool for the general evaluation of the AV loop model – particularly with regard to the three-dimensional distribution of immunohistochemical positive and negative cells.

Beschreibung: An algorithm, based on the wavelet scalogram energy, for automatically detecting events in force-extension AFM force spectroscopy experiments is introduced. The events to be detected are characterized by a discontinuity in the signal. It is shown how the wavelet scalogram energy has different decay rates at different points depending on the degree of regularity of the signal, showing faster decay rates at regular points and slower rates at singular points (jumps). It is shown that these differences produce peaks in the scalogram energy plot at the event points. Finally, the algorithm is illustrated in a tether analysis experiment by using it for the detection of events in the AFM force-extension curves susceptible to being considered tethers.

Beschreibung: Objective To evaluate the safety of rapid cryopreservation for human testicular tissues by comparing the meiotic recombination in the fresh and thawed testis after rapid freezing. Methods Twelve male patients with prostate cancer (PC) who had given birth to healthy children at youth and need to receive surgical removal of testicular tissue at present were selected in this study. Testicular tissues from 4 cases of PC patients were randomly divided into two parts, one part as fresh tissue and the other to receive rapid freezing treatment. Fidelity analysis for homologous genetic recombination and synapsis were performed by immunofluorescence after prepared by a micro-spreading technique. Results The average number of MLH1 foci per cell, autosomal synaptonemal complex (SC) containing 0∼5 MLH1 foci and percent of cells with one MLH1 focus on XY chromosome showed no difference between the fresh and frozen thawed testicular tissues from the same case ( P 〉0.05). And, no significant difference in the frequency of gaps and splits on SCs was observed in fresh and thawed spermatocytes ( P  〉 0.05). Conclusion Rapid cryopreservation showed little effect on the frequency of meiotic recombination and fidelity of synapsis in human spermatocytes from PC patients, and acted as an effective method for preserving male fertility.

Beschreibung: The Pap smear is the primary screening tool for invasive cervical cancer resulting from a persistent infection with oncogenic human papillomavirus (HPV); however, there are the problems such as the inability to distinguish between HPV infection and cervical dysplasia and a low sensitivity remain. We present preliminary findings of a label-free method to detect and classify HPV infection and cervical dysplasia using human cervical fluids. Three experimental groups, defined as normal, HPV-positive, and cervical dysplasia, were evaluated through their Raman spectral patterns for noise-independence, high reproducibility, and uniformity. Clinical diagnosis was performed through liquid-based cervical cytology, HPV test, and cervical histologic examination. Healthy cervical fluids showed a strong Raman intensity at 877 cm −1 (symmetric C–C stretching), and at 963 cm −1 (phosphate), compared to a reference Raman peak at 1003 cm −1 (phenylalanine symmetric ring breath). The HPV-positive cervical fluids showed a strong intensity of a Raman peak at 1448 cm −1 corresponding to C–H deformation vibration mode and the highest similarity between the central and ring zones among the three groups. The cervical dysplasia fluids showed the presence of strong peaks compared to the control and HPV-positive groups. In addition, different Raman spectra were acquired according to HPV type. Therefore, all ranges of cervical fluid-induced Raman spectra could be used to detect the presence of cervical pre-cancer. Raman peak-gated assessment provides a label-free and nondestructive tool for the clinical diagnosis of HPV infection and cervical precancerous changes.

Beschreibung: This study intensely focuses on to the localization and identification of crustacean hyperglycemic hormone (CHH) producing neurosecretory cells in the eyestalk of the blue swimmer crab Portunus pelagicus . Anti- Carcinus maenas -CHH was used to identify the location of CHH neurosecretory cells by immunohistochemistry. Ten pairs of eyestalks were collected from intact adult intermoult female crab and fixed in Bouin's fixative. Eyestalks were serially sectioned and stained with chrome-hematoxylin-phloxine stain. Histological studies show the presence of different types of neurosecretory cells namely A (multipolar), B (tripolar), C (bipolar), D (unipolar), E (oval), and F (spherical) in the medulla interna, externa, and terminalis regions based on their size, shape, and tinctorial properties. The neurohemal organ, sinus gland (SG) was observed laterally between medulla interna and terminalis regions. Immunohistochemical studies showed the presence of distinct CHH-like immunoreactivity in the optic ganglia. Divergent group of neurosecretory cells with varying degree of immunoreactivity with Anti- Carcinus maenas -CHH (low, moderate, and intense reactivity) were identified in medulla terminalis, medulla interna, medulla externa, and sinus gland. The present study maps the various types of neurosecretory cells in the optic ganglia and also shows the presence of CHH-like immunoreactivity in various regions of optic ganglia in P. pelagicus . The presence of these unique neurosecretory cell types with larger cell diameter in medulla terminalis, a region that bears the neurosecretory cell bodies, suggest high secretory activity.

Beschreibung: A two-dimensional (2D) numerical model was used to simulate the use of a phase change material and inner fins incorporated to a PV panel, in order to control the temperature rise of the PV cells at various inclination angles from 0 º to 90º  with respect to vertical at increments of 15°. The PCM (RT25) is placed in a cavity directly in contact with the PV panel. This cavity enclosed on both sides by aluminum layers, and contains extended surfaces (fins). This PV-PCM system is studied numerically using finite volume method. The predicted temperatures have been compared with experimental and numerical data of the literature and a good agreement was obtained for both the isothermal contours and time evolution of the temperature. The  bulk  of  the  PCM  melting  within  the  system  is  dominated  by  natural convection for angle inclination lower than 45 º.  In other hand, for the inclinations higher than 45º the heat transfer in conduction mode increases until at 90º, where natural convection disappears completely and the conduction manifests alone. The obtained results reveals that the temperature of the PV panel increases with the increase of the inclination and that small inclinations (lower than 45 º) allow for a better cooling of this panel.

Beschreibung: In this study we present the simulation results of a small rooftop PV system with a nominal power of 2KWp under the climate of Oujda city (North East of Morocco) using high quality data measured at ground level for a period of one year. The results show that for an annual global horizontal irradiance of 1891KWh/m², the system is able to provide a yearly electrical production of 3230.1 KWh for a total load of 1538 hours/year and with a mean system efficiency of 8.6%. Generally, the integration of PV systems for small utility scale in Eastern Morocco and especially in the building is very promising, and the results of this study can helpthe local political and economical actors in the field of solar energyto develop strategies and programs to enhance the PV integration on buildings.

Beschreibung: Worldwide, power generation from fossil fuels is currently in jeopardy due to carbon dioxide emissions that directly influence the greenhouse effect and thus, climate change. This has led to seek or encourage the use of other sources of power generation, such as hydropower. Small Hydroelectric Plants (SHP) represent a suitable alternative for electric power generation in Colombia due to favorable conditions in its operation and the low environmental impact compared with other available energy sources in the country. SHPs, within the Clean Development Mechanism, are considered a source of clean energy with minimal impacts on the environment. This article presents a review of the existing methodologies for assessing greenhouse gas emissions and the implementation of the ACM0002 methodology in a SHP in Colombia, calculating an updated emission factor in the country.

Beschreibung: ABSTRACT In the past years, the self-assembly of specific proteins has been paid more and more attention due to their significant role in human health and fabrication of new materials. In this article, we explore the effect of reaction conditions on the self-assembly of natural silk sericin protein, including the molecular weight and the concentration of sericin, pH, and metal ions in the reaction system. The results indicate that all these factors, especially species and concentration of metal ions, could influence the self-assembly process of the silk sericin protein. A series of assemblies with various morphologies can be fabricated by modulating the reaction condition. The article may provide some clue for the understanding of the protein self-assembly in the body and a method to fabricate new organic materials with different morphology. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT Phyllotreta striolata (Fabricius) is an important pest of Brassicaceae in Southeast Asia and North America. Using scanning electron microscopy, we observed the external structure, number, and distribution of the antennal sensilla in P. striolata females to discuss the putative function of these sensilla in host location and oviposition behaviors. The antenna of female P. striolata is filiform, composed of a scape, a pedicel, and a flagellum with 9 flagellomeres. Five types of sensilla were identified, including sensilla cheaetica, sensilla trichodea, Böhm bristles, sensilla auricillica, and sensilla basiconica (five subtypes, SB1–SB2). External structure and distribution of antennal sensilla are compared with data from other insect species. In addition, we discuss the possible functions of antennal sensilla based on their characteristics. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT Growth-year authentication has extraordinary significance for plant growth, structure and development research, and has a wide range of applications in value assessment of economic crops. Panax ginseng is the most commonly used medicinal plant in Asian countries. The fix number of growth-year is an important quality evaluation which is difficult to be obtained accurately in current technical conditions. Preliminary authentication theory for growth-year has been described in previous studies using a short-lived perennial medicinal plant ( Paeonia lactiflora pall.) as the research material. In this research, we focused on the growth-year estimation in ginseng cultivars, and attempt to explore the age estimation method for vascular plants according to mathematical simulation of the root structure development. Micro data was obtained from 204 individuals of 3 different kinds of ginseng cultivars, which have a series of gradient age and a clear growth record. Outer diameter of the vascular cambium (b) and the radius of cross section (r) were measured with ordinary stereo microscope. We further designed and established two different kinds of authentication model based on the taproot structure development for growth year authentication ( P and M = K*X 1 a 1 X 2 a 2 ). Moreover, the models were applied to identify the growth year of ginseng without damage using Micro-CT or DEI reconstruction. A potential method, have been recently described, the age of ginseng can be analyzed by telomere length and telomerase activity. However, we found that there are different results indicated in other species. We concluded that microscopic methods perceived currently were provided a more effective means for growth-year authentication. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT In this contribution, they have attempted to develop a labeling technique for in vivo imaging of functionally active plasmid DNA in cyanobacterial cells through its decoration with semiconductor quantum dots (Qdots) as fluorescent nanoprobes. For that purpose biotinylated plasmid slr2060 DNA was conjugated with Qdots-streptavidine. The intact DNA was visualized in a single green color by light microscopy. These Qdots-DNA conjugates were capable of expressing the acyltransferase enzyme. Qdots-DNA conjugates and confocal microscope imaging technique were adopted to visualize the gene transport across the membrane of the live cyanobacteria cell in real time. Long-term kinetic study enabled to reveal the steps of extracellular and intracellular microenvironment for plasmid transportation into the live cell. To confirm these processes a confocal microscope and indicator plate assay test were applied in tandem. In this contribution, Qdots-labeled plasmid DNA was utilized for the first time for long-term intracellular imaging studies in cyanobacteria species PCC6803. The results showed that the Qdots-labeled plasmid DNA detection could be used as a powerful labeling technique for visualization of exogenous DNA entry and tracking into living cells by confocal microscopy. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT The present study was designed to investigate the relationships between clinicopathological findings and the resorptive conditions of root apices of teeth with periodontitis. The samples included 21 root apices with large periapical radiolucent lesions. The preoperative computed tomography (CT) and intraoperative findings were correlated with the presence, extension, and the progression pattern of periapical resorption using a scanning electron microscope. The subjects' age, gender, chief complaint, type of tooth, percussion test results, size of periapical lesion using CT, and intraoperative findings were recorded. All apicoectomies were performed under an operative microscope for endodontic microsurgery. A significant large size was observed in cystic lesions compared with granulomatous lesions. The cementum surface at the periphery of the lesion was covered with globular structures (2–3 μm in diameter). Cementum resorption started as small defect formations at the surface. As the defect formation progressed, a lamellar structure appeared at the resorption area, and the size of globular structures became smaller than that of globules at the surface. Further resorption produced typical lacuna formation, which was particularly observed in fracture cases. The most morphologically severe destructive pattern of dentin resorption was observed in large cystic lesions. This study is the first report to elucidate the relationships between three clinical types of undesirable periapical lesions: (1) undertreatment, (2) periapical fracture, (3) macro-level resorption, and the microstructure of external root resorption including from small defects at the cementum surface to a significant destructive pattern inside the dentin. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: In this work, we present the method followed to construct a pseudophase diagram of two phospholipids: 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphoethanolamine and 1-palmitoyl-2-oleoyl- sn -glycero-3-phospho-(1′- rac -glycerol). Two different techniques, DSC and AFM, have been used based in the determination of the onset ( T onset ) and completion ( T offset ) temperatures of the gel-to-liquid crystalline phases ( L β L α ), the first from the endotherms from liposomes and the second from the topographic images of supported lipid bilayers. The features of both phase diagrams are discussed emphasizing the influence of Ca 2+ presence and the substrate (mica) on the transition undergone by the phospholipid mixture. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT The micro-X-ray fluorescence by synchrotron radiation (μ-XRF) is a method to determine the composition of tissues without destroying the samples. However, this technique has never been used for the analysis of mesenchymal stem cells (MSC). This study compared different protocols for fixing, storing, preserving, and establishing the correct numbers of dental derived MSC submitted to μ-XRF analysis. Stem cells were obtained from human dental tissue. After cell expansion, and MACS isolation, the samples were fixed and the following quantities of cells 1 × 10 4 to 1 × 10 7 were divided in two groups: G1 : fixed in 4% paraformaldehyde diluted in phosphate-buffered saline solution, and G2: fixed in 4% paraformaldehyde diluted in MilliQ water. The G1 cells showed precipitation of chemical components from the solution resulting in the formation of salt crystals while G2 cells were clear and almost transparent in the sample holder. With regards to cells concentration, the best results occurred when four droplets of 1 × 10 7 cells were analyzed. This work shows that to identify and study the distribution of trace elements in MSC by μ-XRF, the best protocol is fixation in 4% paraformaldehyde diluted with MilliQ water at 4°C and a concentration of four incremental droplets of 1 × 10 7 cells. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT Objectives We sought to devise and test a multifunctional contrast dye agent for X-ray based digital radiography (DR) or computer tomography (CT), magnetic resonance imaging (MRI), and colored staining in ex vivo validation part of animal experiments. Materials and Methods: The custom-formulated contrast dye namely red iodized oil (RIO) was prepared by solubilizing a lipophilic dye Oil Red O in iodized poppy seed oil (Lipiodol or LPD) followed by physicochemical characterizations. To explore and test the utility of RIO, normal rats ( n  = 10) and rabbits ( n  = 10) with myocardial infarction (MI) were euthanized by overdose of pentobarbital for infusion of RIO through catheterization. The bodies and/or excised organs including heart, liver, spleen, kidneys, pancreas, and intestines of the rats and rabbits were imaged at clinical mammography, CT and MRI units. These images were qualitatively studied and quantitatively analyzed using Wilcoxon Rank test with a P value 〈 0.05 being considered of a statistically significant difference. Imaging findings were verified by histomorphology. Results : All experimental procedures were carried out successfully with the use of RIO. T1 and T2 relaxation time was 234.2 ± 2.6 ms and 141.9 ± 3.0 ms for RIO, close to that of native LPD. Proton ( 1 H) NMR spectroscopy revealed almost identical profiles between RIO and native LPD. The clinical mammography unit, 128-slice CT scanner and 3.0T MRI magnet were well adapted for the animal experiments. Combined use of RIO with DR, MRI, CT and histology enabled microangiography of the organs, 3D visualization of rat pancreas, validation of in vivo cardiac quantification of MI and cause determination of the rabbit death after coronary occlusion. RIO appeared as red droplets and vacuoles in vessels by frozen and paraffin sections. Image analysis showed the superiority of DR images, which provided better overall image quality (4.35 ± 0.49) for all analyzed liver vessel segments. MRI images revealed moderate to good overall image quality ratings (3.45 ± 0.52). Comparing the signal intensities of vessel and liver with different MRI sequences, all P values were 〈0.01. Conclusions: RIO proved to be a multifunctional contrast dye, which could be applied as an imaging biomarker for tissue vascularity or blood perfusion, for visualization of organ anatomy and for ex vivo validation of in vivo animal experiments. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT Nitric oxide (NO) is produced by nitric oxide synthases (NOSs) and plays an important role in all levels of reproduction from the brain to the reproductive organs. Recently, it has been discovered that all germ cells and Leydig cells in the cat testis exhibit stage-dependent nuclear and cytoplasmic endothelial (eNOS) and inducible (iNOS)-NOS immunoreactivity and cytoplasmic nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) reactivity. As a continuation of this finding, in this study, cellular localization of NADPH-d and immunolocalization and expression of all three NOS isoforms were investigated in the intratesticular (tubuli recti and rete testis), and excurrent ducts (efferent ductules, epididymal duct and vas deferens) of adult cats using histochemistry, immunohistochemistry and western blotting. NADPH-d activity was found in the midpiece of the spermatozoa tail and epithelial cells of all of ducts, except for nonciliated cells of the efferent ductules. Even though the immunoblotting results revealed similar levels of nNOS, eNOS and iNOS in the caput, corpus and cauda segments of epididymis and the vas deferens, immunostainings showed cell-specific localization in the efferent ductules and region- and cell-specific localization in the epididymal duct. All of three NOS isoforms were immunolocalized to the nuclear membrane and cytoplasm of the epithelial cells in all ducts, but were found in the tail and the cytoplasmic droplets of spermatozoa. These data suggest that NO/NOS activity might be of importance not only for the functions of the intratesticular and excurrent ducts but also for sperm maturation. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT The Atomic Force Microscopy (AFM) technique appears as a central tool for the characterization of DNA adsorption onto lipid interfaces. Regardless of the huge number of surveys devoted to this issue, there are still fascinating phenomena in this field that have not been explored in detail by AFM. For instance, adsorption of DNA onto like-charged lipid surfaces mediated by cations is still not fully understood even though it is gaining popularity nowadays in gene therapy and nanotechnology. Studies related to the complexation of DNA with anionic lipids as a non-viral gene delivery vehicle as well as the formation of self-assembled nanoscale DNA constructs (DNA origami) are two of the most attractive systems. Unfortunately, molecular mechanisms underlying the adsorption of DNA onto anionic lipid interfaces remain unclear so far. In view of that, AFM becomes an appropriate technique to provide valuable information to understand the adsorption of DNA to anionic lipid surfaces. As a second part of this review we provide an illustrative example of application of the AFM technique to probe the DNA adsorption onto a model lipid monolayer negatively charged. Microsc. Res. Tech., 2016 . © 2016 Wiley Periodicals, Inc.

Beschreibung: All the existing energy sources have environmental, social and economic impacts. The greenhouse effect which results global warming, air pollution, and energy security have led to increasing interest and more development in energy conservation. Electrical energy conservation is one of them. In this research, critical electrical energy situation in one of the developing countries in the world-Bangladesh was considered in general. It is possible to serve maximum number of electrical energy consumers by maintaining proper use of the electrical energy. During hot summer the electrical power shortage is about 1000 MW to 1500 MW each year. If energy conservation is achieved through human behavior change, around 390 GWh of electrical energy per month and 4,683 GWh per year can be saved in Bangladesh.  A related case study is conducted for this research. It is possible to save the electrical energy through behavior change from 3% to 20%.

Beschreibung: Renewable energy sources are fast growing. Nowadays much effort has been made by inventors to devise new and more efficient configurations of wind turbines. This paper describes mechanical design and resultant-force dynamic simulation of innovative wind turbine structure HASWT. The innovation in wind turbine structure includes flat shape of its blades and their orientation that minimizes the axial component of wind force that generates, in turn, disturbing axial forces on the rotor bearing. Instead, all power of the wind is spent to generate useful rotary or radial force that drives the rotor shaft. This enhances the efficiency of the turbine as compared to complex shape blades in traditional HAWT. The distinctive feature of the system is an oscillating shield that automatically protects the generator shaft at extreme wind speeds from over speeding, and therefore generating power above its capacity or even causing physical damages. The center-point force dynamic load models on the rotor blades have been derived for various wind conditions. The simulation algorithms have been tested in MATLab Simulink environment. The results of simulation show the efficacy of the system and an advantage of using this system with the over speed shield protection

Beschreibung: Solar energy is a potential resource among the various renewable energy options which is clean, inexhaustible and eco-friendly. The development of usage and installation of PV system needs a suitable solar policy making plan through proper assessment of solar PV Energy potential in Odisha. This study presents a very simple methodology for estimating the photovoltaic potential of Odisha using the PVGIS online software. The presented method is also useful in determining the PV potential of almost any state, country and region that covers the database of PVGIS. The study divides the total geographic area of Odisha into 1195 square areas with each having its particular coordinate approximately at the midpoint of the location. The PVGIS software is used to evaluate the value of incident solar radiation and generated PV energy at each site. The evaluation of PV Energy Potential includes implementation of four cases that differentiates the PV system according to its technology and structure. The evaluation of energy potential on each four cases estimates two important parameters that are total incident Global radiation for a year and total annual PV Energy production. PV potential of Odisha using the estimated data is presented in the form of rasterized plot.