Normal Room Conditions Research Articles

Titanium oxide:fullerene composite films as electron collector layer in organic solar cells and the use of an easy-deposition cathode

Here is reported the use of a titanium oxide:fullerene (TiOx:PC71BM) composite film as electron collector layer in organic photovoltaic devices (OPV cells). OPV cells were fabricated under the bulk heterojunction architecture: the active layer was a blend of either the photoconductor polymer MEH–PPV or P3HT with the fullerene derivative PC71BM. As cathode the eutectic alloy of Bi, In and Sn, known as Field’s metal, was used. The melting point of this alloy is above 62°C, which makes it suitable for a vacuum-free deposition process and easy and fast device test. Cell fabrication and testing were carried out at normal room conditions. For OPV cells based on MEH–PPV, the composite thin electron collector layer improved the power conversion efficiency (η) from 1.12% to 2.07%, thus the η increase was about 85%. Meanwhile, for devices based on P3HT the use of the composite film improved the photocurrent in almost 1mA/cm2 and the efficiency slightly increase from 2.48% to 2.68%.

Stereological analysis of cornu ammonis in prenatally stressed rats: a heuristic neurodevelopmental model of schizophrenia.

The hippocampus has been implicated in pathophysiology of schizophrenia. Prenatal stress is a contributing risk factor for a wide variety of neuropsychiatric diseases including schizophrenia. This study examined long-term effects of prenatal restraint stress on the stereological parameters in the Cornu Ammonis (CA) of adult male rats as an animal model of schizophrenia. Wistar pregnant dams in experimental group were stressed in a cylindrical Plexiglas restrainer daily for 1 hr during last week of gestation. Controls remained in the animal room and were exposed only to normal animal room conditions. At 2 months of age, the volume of the pyramidal cell layer of the CA, the numerical density and the somal volume of the respective neurons were assessed in the male offspring generated from stressed and control pregnancies. Cavalieri's principle, physical disector and nucleator were applied for stereological analyses. This study showed that prenatal stress significantly decreased the volume of CA3 pyramidal cell layer and the individual somal volume of CA3 pyramidal neurons. However, there were no markedly differences in the numerical density, total number of CA3 pyramidal neurons and stereological parameters in CA1 of prenatally stressed and control animals. These data indicate that prenatal stress exposure induced neuronal changes in the CA3 subfield of hippocampus which are similar to what is observed in schizophrenia.

PRELIMINARY STUDY OF WATER CONTENTS AND SIGNAL BEHAVIOR IN FINGERNAIL/EPR DOSIMETRY

Heating method using electric heater was used to reduce water content in fingernail clippings. Authors found that low water content is helpful to measure EPR signal of fingernail sample with enhanced variability. Generally, natu-ral dehydration happens in normal room condition at least one month and needs much time for using in experiment. So, artificial heating method is applied in this study for time savings. Fingernail samples were tested to find effect of water content to the EPR signal on microwave power levels for dosimetry. Low water content in fingernail reduced variability of EPR signal and makes it possible to measure accurate EPR signal. It also made it possible to measure constant movement of EPR signals on several microwave power levels. Although this meth-od was difficult to apply directly in fingernail/EPR dosimetry, we, authors, believe that this heating method would be useful to differentiate MIS2 and RIS which are generally located at the same g-factor and almost impossible to be identified with each other.

Effect of prenatal stress on density of NMDA receptors in rat brain

N-methyl-d-aspartate (NMDA) receptors are important excitatory receptors which contribute to many brain functions. Altered NMDA receptor levels cause maldevelopment of corticostriatal and corticolimbic pathways, which is a neurobiological predisposing factor for development of epilepsy, schizophrenia and other idiopathic psychotic disorders. It was hypothesized that prenatal stress could play a role in pathophysiology of these disorders by affecting expression of the receptors through releasing corticosterone. Sixty-eight virgin female Wistar rats were selected and mated with male rats with the same genotype. Then, the pregnant rats were subjected to restraint or predator stress on 15th, 16th and 17th gestation days. Prenatal stress consisted of restraint or predator stresses of the dams under normal room conditions. After parturition, the pups were studied in terms of density of NMDA receptors in brain at different time points. Meanwhile, blood sample was obtained and corticosterone blood level (CBL) was measured. The pups were then compared with the pups born to unstressed dams. Stress induced significant rise in CBL and NMDA receptors in brain of the offspring. CBL was significantly higher among the stressed rats compared to the control ones; there was significant difference between the two stresses and between the two sexes. The male pups were affected more severely. Stressful events during gestation had important effects on NMDA receptors of the offspring. It can be concluded that stress-induced elevation of NMDA receptors and corticosterone might mediate altered susceptibility to epilepsy and decrease ability of learning and memory and other stress-induced neurologic disorders.

The Effect of Prolonged Light Intensity Exercise in the Heat on Executive Function

When people are involved in outdoor activities, it is important to be able to assess a situation and make rational decisions. The goal of this study is to determine the effects of 90 minutes of light-intensity exercise in a hot environment on executive functioning capabilities of healthy individuals. In this prospective laboratory study, 40 healthy male and female subjects 18 to 45 years of age performed treadmill exercise while wearing athletic clothing and a backpack in either a hot or temperate environment. Vital signs, core and skin temperature, and perceptual measures (thermal sensation, sweating, comfort, and perceived exertion) were measured before, during, and after the treadmill test. Cognitive function was measured before and after the treadmill test using the Wisconsin Card Sorting Test (WCST) and a Psychomotor Vigilance Test (PVT). Subjects in the hot condition reached a similar core temp of 38.2° ± 0.5°C vs 37.7° ± 0.3°C (P = .325) in the temperate group but had a higher heart rate (P < .001) and skin temperature (P < .001). Hot and normal temperature groups did not differ in their PVT performance. There were more correct responses (P < .001), fewer errors (P < .001), and more conceptual responses (P = .001) on the WCST after exertion in both the hot room and normal temperature room conditions. Perseverations and perseverative errors (P = .002) decreased in both groups after exertion. Conditions of mild heat stress coupled with modest rehydration and short hiking treks do not appear to negatively affect executive function or vigilance.

Memristive Behavior in Electrohydrodynamic Atomized Layers of Poly[2-methoxy-5-(2'-ethylhexyloxy)–(p-phenylenevinylene)] for Next Generation Printed Electronics

Poly[2-methoxy-5-(2'-ethylhexyloxy)–(p-phenylenevinylene)] (MEH:PPV) based organic memristor (memory resistor) has been fabricated on the indium–tin oxide (ITO) coated poly(ethylene terepthalate) (PET) substrate by the electrohydrodynamic atomization (EHDA) technique. Thin jet containing MEH:PPV polymer was generated through a capillary under electrical stresses. The jet was broken into small droplets by adjusting the distance from nozzle to substrate and collected over the substrate under normal room conditions, consequently a high quality layer of MEH:PPV was achieved with an average thickness of 168 nm. The layer was morphologically characterized by a field emission scanning electron microscope (FESEM) analysis. X-ray photoelectron spectroscope (XPS) analysis was also carried out to confirm the chemistry of the deposited material. Electrically, ITO/MEH:PPV/Ag fabricated memristor was found to be switchable between high state and low state between ±4 V. The research work provides the memristive behavior in electrohydrodynamic atomized layers of MEH:PPV to be used for the next generation printed electronics application.

ZrO2 flexible printed resistive (memristive) switch through electrohydrodynamic printing process

Electrohydrodynamic (EHD) printing technique has been deployed to fabricate flexible printed resistive (memristive) switch in a metal–insulator–metal sandwich structure of Ag/ZrO2/Ag on a polyimide substrate under normal room conditions. The top and bottom electrodes were deposited through the jetting of EHD printing and the active layer of ZrO2 between two electrodes was deposited through the atomization of EHD printing process. The achieved dimensions of the printed device were around 100μm×100μm with the thickness of the bottom electrode, switching layer and top electrode were around 230nm, 680nm and 420nm respectively. The fabricated device showed stable bipolar memristive switching behavior around ±3V. The reversible resistive switching behavior was measured with the high OFF/ON ratio of 100:1. The device kept on exhibiting memristive characteristics after being physically flexed over 500 times that shows its viability for flexible electronics applications.

In vitro propagation of almond (Prunus dulcis) cv. Merced

Forced and unforced shoot tips were surface sterilized with different sterilant regimes and incubated under normal culture room conditions. Surface sterilization of explants with mercuric chloride 0.1% (w/v) for 10 min. was found effective in improving culture asepsis (51.66%) and explant survival (55.00%). Higher values for both these parameters were recorded with forced explants in comparison to unforced ones. Main effect of growth regulators and media was significant on explant establishment which was maximum (66.66%) on ½ MS media containing BAP + IBA (0.50+0.01 mg/l). Callusing at the base of initiating cultures was minimum (24.58%) with BAP+IBA (0.25+0.01 mg/l). Microshoots from the established cultures were subcultured on the MS media supplemented with BAP and NAA alone or in combination for axillary shoot proliferation. Maximum proliferated cultures (86.66%) with maximum shoot number/explant (15.61) and proliferation grade (4.00) was obtained with BAP+NAA ( 0.40 + 0.01 mg/l). BAP was found superior to NAA during axillary shoot proliferation. Microshoots (10–15 mm) from proliferated cultures were subcultured in root induction medium (MS medium supplemented with IBA) and incubated under darkness for 10 days at 24±1 oC and then transferred to root development medium (hormone-free MS medium) and incubated under normal culture room conditions. Highest rooting of microshoots (93.33%) with maximum root number/shoot (5.90) and root length (43.00 mm) was obtained with IBA (1.0 mg/l).

Numerical Study of Non-Gray Radiation and Natural Convection Using the Full-Spectrum k-Distribution Method

The interaction of non-gray radiation and natural convection in a 2-D cavity is studied numerically. The aim of this work is to analyze the thermal and flow behaviors of real cases with a small temperature difference using the full-spectrum k-distribution method. In addition, the results are obtained for different medium assumptions like pure convection, transparent medium, and gray medium to investigate which assumption is appropriate to be used instead of non-gray calculations. The results show that the gray medium assumption for radiative heat transfer is suitable to be used in cavities with normal air mixture at normal room conditions.

Combined heat transfer of radiation and natural convection in a square cavity containing participating gases

This article deals with analyzing the effect of radiative heat transfer on natural convection heat transfer in a square cavity under normal room conditions. The governing equations of natural convection and radiative transfer are solved simultaneously to obtain the temperature, velocity and heat flux distributions inside the participating medium. The finite volume method has been adopted to solve the governing equations and the discrete ordinates method (DOM) is used to model the radiative transfer in absorbing-emitting media. The radiative–convective model is validated by comparison with test cases solutions from the literature. Then, the effects of Rayleigh number from 10 2 to 10 6 and optical thickness in a broad range from 0 to 100 on temperature and velocity distributions and Nusselt numbers are investigated. The results show that even under normal room conditions with a low temperature difference, the radiation plays a significant role on temperature distribution and flow pattern in the cavity. Also, several interesting effects of radiation are observed such as a sweep behavior on the isotherms, streamlines and velocity distributions of the cavity along the optical thickness and a reverse behavior on maximum stream function and convective Nusselt number at different Rayleigh numbers.

Prenatal stress potentiates pilocarpine-induced epileptic behaviors in infant rats both time and sex dependently

Stressful events during gestation have important effects on the later physical and mental health of the offspring. In the study described here, the pilocarpine-induced seizure model was used to test the hypothesis that prenatal stress affects seizure susceptibility in infant rats. Prenatal stress consisted of daily restraint of the dam under normal room conditions (for 120 minutes, twice daily) during the first, second, and third weeks of gestation. The pups were then compared with pups born to unstressed dams. Both second- and third-week-gestation stress significantly reduced pilocarpine-induced seizures in 19-day-old rat offspring, as compared with nonstressed control offspring. Mid- and late-gestation stress increased the rate and time of tonic–clonic seizures. Mortality rate 2 and 24 hours after pilocarpine administration increased significantly in all stressed rats. Stress induced a significant rise in circulating corticosterone levels (2- to 8-fold, P < 0.001) in the offspring. Female offspring differed little from male offspring with respect to blood corticosterone levels and epileptic behaviors. These findings indicate that prenatal stress, particularly during the second and third weeks of pregnancy, may play an important role in increasing seizure vulnerability in the unborn offspring. Female rats are more resistant to stress than males probably because of the lower susceptibility of their hypothalamic–pituitary–adrenal axis.

N[sub 2]-Based Thermal Passivation of Porous Silicon to Achieve Long-Term Optical Stability

A technique is presented to create porous silicon (PS) thin films with long-term optical stability when exposed to normal room conditions. This technique requires the thin films to undergo a rapid thermal annealing treatment at a relatively low temperature of 600°C in N 2 atmosphere for 6 min. Annealing at such a low temperature enables the surface passivation of PS via nitridation without causing the excessive roughness and sintering widely observed at higher annealing temperatures. A mechanism similar to the Haber process is proposed to explain the surface nitridation, in which the nitrogen atmosphere interacts with the as-anodized hydrogen surface species.

Storing Pollen of Two Olive Cultivars: ‘Rasie’ and ‘Nabali Baladi’

This study was conducted on ‘Rasie’ and ‘Nabali Baladi’ olive cultivars to establish short-, mid-, and long-term pollen storage technique. Pollen was stored in normal room condition, refrigerator (4°C), freezer (−5°C), and cryostorage (−80°C) for up to 52 weeks. Pollen was in vitro germinated on solid-agar media, and its viability was tested using 2, 3, 5–triphenlytetrazolium chloride. Cryopreserved pollen under −80°C gave the best results, and refrigerated and frozen pollen gave convenient results. Under room conditions, pollen of the two cultivars has lost its germinability and viability gradually, and after 52 weeks the pollen was nonviable.

EFFECT OF STORAGE METHODS AND PERIODS ON GERMINATION OF ONION SEED

Two laboratory experiments were conducted at Gemmeiza Agriculture Research Station (Gharbeia Governorate) to study the effect of both storage and methods of storage on viability of onion seed during the period from August 2006 to August 2008. Randomize Complete Blocks Design with three replications was used. The results clearly showed that : 1- There was a progressive decline in germination percentage with each increase in the storage period. The decline in germination percentage after 12 months was 10.36 % and 21.42 % after 24 months. Seed germination percentage was markedly affected by methods of storage. Utilizing of polyethylene bags under Frigidaire at 5-8 oC or freezing resulted in higher seed germination percentage. There was a significant interaction effect of period and method of storage. The higher percentage of germination was observed under the treatment of storage period for 4 months in paper bags without and additions under normal room conditions. 2- Germination rate (days) was markedly affected by storage period, but differences between treatments were not always significant. There are a progressive increase in number of days to complete germination with each increase in storage period. Germination rate was significantly affected by storage method. The fastest rates of germination were observed with storage of onion seed in polyethylene in normal room conditions. 3- Seedling length was markedly affected by storage period. Storage at 4 and 8 months were associated with highest length of seedlings i.e . 3.85 and 3.84 cm), respectively. Seedling length was markedly affected by storage method. The maximum seed length (3.84 cm) was observed with storage of seed in polyethylene bags without any additions under normal room conditions It can be concluded that storage onion seed for four months in paper bags in normal room conditions followed by burlap bags in normal room conditions gave the best results in germination percentage and other seedling parameters.

Dynamic Effective Mass of Granular Media

We develop the concept of frequency dependent effective mass, M[over ](omega), of jammed granular materials which occupy a rigid cavity to a filling fraction of 48%, the remaining volume being air of normal room condition or controlled humidity. The dominant features of M[over ](omega) provide signatures of the dissipation of acoustic modes, elasticity, and aging effects in the granular medium. We perform humidity controlled experiments and interpret the data in terms of a continuum model and a "trap" model of thermally activated capillary bridges at the contact points. The results suggest that attenuation of acoustic waves in granular materials can be influenced significantly by the kinetics of capillary condensation between the asperities at the contacts.

Shallow donor states induced in ZnSe:Au single crystals by lattice deformation

Photoluminescence (PL) spectra are investigated in n-ZnSe single crystals at different temperatures from 4.4 to 300 K immediately after doping with Au from melt of Se+Au or Zn+Au and after storage of the doped samples for 4 years in the dark under normal room conditions. Due to the formation of Aui interstitial donors in the n-ZnSe:Se:Au crystals with time, the origin of the near band edge PL changes from acceptor-bound to donor-bound excitons. Taking into account the results of PL characterization, we proposed that the Aui donors are generated by displacement of Au ions from regular lattice sites to interstitial sites with the help of lattice deformation forces. Transport measurements show dramatic increase in the electrical conductivity and the free electron concentration after storage of the n-ZnSe:Zn:Au crystals, thus confirming the proposed model.

Self-Affine Quasi-Static Fracture of Soda-Lime Glass

In the present work we discuss the self-affine properties of the fracture surfaces of sodalime glass obtained under quasi-static conditions. The fracture surfaces are generated using a threepoint bending system in normal room conditions and under high humidity conditions. The surfaces were recorded both by Scanning Electron Microscopy and Atomic Force Microscopy, and their selfaffine properties are characterized using the Variable Bandwidth method. For both conditions it is observed that the major part of the fracture surface is occupied by the mirror zone. On the other hand, the self-affine analysis reveals that for both conditions the roughness exponent has values centred at around 0.58 with moderate dispersion, in agreement with previous results. Our findings support the hypothesis of the existence of a characteristic roughness exponent for quasi-static fracture with a value that is significantly lower than the value of 0.8 reported for rapid fracture conditions.

Stability of Iodine in Salt Fortified with Iodine and Iron

Determining the stability of iodine in fortified salt can be difficult under certain conditions. Current methods are sometimes unreliable in the presence of iron. To test the new method to more accurately estimate iodine content in double-fortified salt (DFS) fortified with iodine and iron by using orthophosphoric acid instead of sulfuric acid in the titration procedure. A double-blind, placebo-controlled study was carried out on DFS and iodized salt produced by the dry-mixing method. DFS and iodized salt were packed and sealed in color-coded, 0.5-kg, low-density polyethylene pouches, and 25 of these pouches were further packed and sealed in color-coded, double-lined, high-density polyethylene bags and transported by road in closed, light-protected containers to the International Council for the Control of Iodine Deficiency Disorders (ICCIDD), Delhi; the National Institute of Nutrition (NIN), Hyderabad; and the Orissa Unit of the National Nutrition Monitoring Bureau (NNMB), Bhubaneswar. The iodine content of DFS and iodized salt stored under normal room conditions in these places was measured by the modified method every month on the same prescribed dates during the first 6 months and also after 15 months. The iodine content of DFS and iodized salt stored under simulated household conditions was also measured in the first 3 months. After the color code was broken at the end of the study, it was found that the DFS and iodized salt stored at Bhubaneswar, Delhi, and Hyderabad retained more or less the same initial iodine content (30-40 ppm) during the first 6 months, and the stability was not affected after 15 months. The proportion of salt samples having more than 30 ppm iodine was 100% in DFS and iodized salt throughout the study period. Daily opening and closing of salt pouches under simulated household conditions did not result in any iodine loss. The DFS and iodized salt prepared by the dry-mixing method and stored at normal room conditions had excellent iodine stability for more than 1 year.

Shallow donor states of Ag impurity in ZnSe single crystals

The Hall coefficient, electrical conductivity and electron mobility are investigated in Ag-doped n-ZnSe single crystals at temperatures between 8 and 500 K immediately after doping the samples and after storing them for 5 years under normal room conditions in darkness. The formation of donor-type Agi interstitial defects stimulated by time is found for the first time. After 5 years storage, the samples show a dramatic increase in the electrical conductivity, free electron concentration and concentration of shallow donors. A model that explains these changes by the displacement of Ag ions into interstitial sites due to lattice deformation forces is proposed. The formation of an Ag-donor impurity band in n-ZnSe:Zn:Ag crystals stored at room temperature is also studied.

A measuring system for the time variation of size and charge of a single spherical particle and its applications

A single charged particle is trapped in a simple quadrupole electrode assembly and oscillated by means of a controlled electric field. A laser Doppler velocimeter (LDV) of the fringe mode is used for detecting the amplitude and phase lag of the particle oscillation with respect to the driving ac field. A unique method for the LDV signal processing is presented that takes the advantage of the sinusoidal oscillation of the particle at a known frequency. Superimposed to the ac drive, a dc drive is added for highly accurate measurements of particle size and charge. This enables us also to discriminate the polarity of charge without Bragg cells. In this paper, the basic principle of the method of the size and the charge measurements is explained and the accuracy of the measurements is demonstrated experimentally. The errors in the size and charge measurements, respectively, are less than 1% and 3% with a confidence coefficient of 99%. Since this apparatus repeats the measurements every 0.3 s for a single particle, the errors can be reduced to 0.1% and 0.3% when the measured values over a period of 30 s, or over 100 data are averaged. As some areas of its applications, experimental data are presented on the Rayleigh instability of evaporating charged droplets. It is shown that there are three types of Rayleigh fission. One of the types seemed to show occurrence of air breakdown around a micron sized spherical particle, which has not been reported so far. However experiments in highly insulating gas ( SF 6 ) revealed that it was not the case but a type of Rayleigh fission. Nevertheless the experimental results gave important information on the charge limit of spherical solid particle due to electric breakdown in air at normal room conditions. Some cares to ensure the advantages of the present method are presented, and possible improvements of the apparatus are also suggested for future use.