Relevance of processing parameters for grain growth of metal halide perovskites with nanoimprint

The quality and the stability of devices prepared from polycrystalline layers of organic–inorganic perovskites highly depend on the grain sizes prevailing. Tuning of the grain size is either done during layer preparation or in a post-processing step. Our investigation refers to thermal imprint as the post-processing step to induce grain growth in perovskite layers, offering the additional benefit of providing a flat surface for multi-layer devices. The material studied is MAPbBr3; we investigate grain growth at a pressure of 100 bar and temperatures of up to 150 °C, a temperature range where the pressurized stamp is beneficial to avoid thermal degradation. Grain coarsening develops in a self-similar way, featuring a log-normal grain size distribution; categories like ‘normal’ or ‘secondary’ growth are less applicable as the layers feature a preferential orientation already before imprint-induced grain growth. The experiments are simulated with a capillary-based growth law; the respective parameters are determined experimentally, with an activation energy of Q ≈ 0.3 eV. It turns out that with imprint as well the main parameter relevant to grain growth is temperature; to induce grain growth in MAPbBr3 within a reasonable processing time a temperature of 120 °C and beyond is advised. An analysis of the mechanical situation during imprint indicates a dominance of thermal stress. The minimization of elastic energy and surface energy together favours the development of grains with (100)-orientation in MaPbBr3 layers. Furthermore, the experiments indicate that the purity of the materials used for layer preparation is a major factor to achieve large grains; however, a diligent and always similar preparation of the layer is equally important as it defines the pureness of the resulting perovskite layer, intimately connected with its capability to grow. The results are not only of interest to assess the potential of a layer with respect to grain growth when specific temperatures and times are chosen; they also help to rate the long-term stability of a layer under temperature loading, e.g. during the operation of a device.

Concept of Kshara Nirmana Out of Kanji with Reference to Rasayansara- A Pharmaceutico-Analytical Study

Kanji (sour rice gruel) is an acidic fermented preparation mentioned in many of the Ayurveda classics for various purpose like therapeutic use, pharmaceutical processes etc. A special method of kanji preparation is mentioned in Rasaratnasamuchchaya commentary by Acharya Dattatreya Anant Kulkarni and similar preparation is also mentioned in Rasayansara book recommended for the Parada samskara (mercurial processes) with some difference in ingredients. Kshara (alkaline preparation/ alkali) is an important preparation mentioned in classics. In Rasayansara text, Acharya Shyamsundar Vaishyaji has described a unique method of Kshara nirmana out of the leftover material of the Kanji. This kind of innovative methods should be adopted to recycle the leftover waste matters. It will help in regenerate the new pharmaceutical product. Here an attempt has been done by preparing the kanji and the kshara out of its residue material as mentioned in Rasayansara. First Kanji was prepared as per the reference of Rasayansara book and the leftover after filtration was dried. The kshara was prepared out of this dried leftover. Organoleptic and physicochemical analysis of the prepared kshara was done. The average yield of obtained kshara was 4.88%. The moisture content of the final product found very less while total ash value found on higher side. The pH value suggests its alkaline nature. It shows good solubility in various solvents and good water-soluble extractive value. Exploration of such innovative procedures where waste stuff is been recycled should be increased in present time.

The impact of growth regulators on grape varieties in the Urals

The article presents data on the effectiveness of the use of drugs on the structural components of the productivity of grape varieties. Research objects of growth regulators are Zircon and Mival Agro. Tests were carried out on table grape varieties Arkadia and Kodryanka. The same cultivars without treatment served as control. In the experiment with the use of Mival Agro the maximum indicator of the average bunch weight of the Arkadia variety was higher by 28.0% in comparison with the control, for the Kodryanka variety the indicator increased by 30.2%. In terms of productivity in the bush in the Arkadia variety the increase was 70.8%, in the Kodryanka grape variety it was 77.5% higher than the control variant when exposed to a similar preparation. Processing of experimental bushes in the variant Mival Agro showed the maximum increase in yield per hectare in the variety Arkadia by 70.0 %, in the variety Kodryanka by 78.1 % in comparison with the control option. Growth regulators have a positive effect on the productivity and yield of grape varieties, the most significant indicators are in the variants of the experiment with the use of the drug Mival - Agro.

Surface-Bound Humic Acid Increased Propranolol Sorption on Fe3O4/Attapulgite Magnetic Nanoparticles

This study explored the feasibility of utilizing a novel sorbent humic acid (HA) coated Fe3O4/attapulgite (MATP) magnetic nanoparticles (HMATP) for the sorption of propranolol from aqueous solutions. MATP and bare Fe3O4 nanoparticles were also synthesized under similar preparation conditions. The FTIR, Zeta potential, XRD, VSM, TEM, and TGA analyses were conducted to characterize the sorbent materials. The effects of pH, sorbent dosage, ionic strength, HA in the aqueous solution, contact time and initial sorbate concentration on sorption of propranolol were investigated using batch sorption experiments. The results suggested that the sorption capacity of HMATP showed little change from pH 4 to 10. Na+ and Ca2+ slightly inhibited the sorption of propranolol on HMATP. While HA in solution enhanced both MATP and HMATP, which indicated that HMATP can resist HA interference in water. Further, the less leaching amounts of Fe and HA suggested a good stability of HMATP. In all conditions, sorption capacity of propranolol on HMATP was obviously higher than that on MATP, which indicated that surface-coated HA played an important role in the propranolol sorption process. Electrostatic interaction, cation exchange, hydrogen bonding, and π–π electron donor acceptor interactions were considered as the sorption mechanisms.

Acute dopamine receptor blockade in substantia nigra pars reticulata: a possible model for drug-induced Parkinsonism

Dopamine (DA) depletion modifies the firing pattern of neurons in the substantia nigra pars reticulata (SNr), shifting their mostly tonic firing toward irregularity and bursting, traits of pathological firing underlying rigidity and postural instability in Parkinson’s disease (PD) patients and animal models of Parkinsonism (PS). Drug-induced Parkinsonism (DIP) represents 20–40% of clinical cases of PS, becoming a problem for differential diagnosis, and is still not well studied with physiological tools. It may co-occur with tardive dyskinesia. Here we use in vitro slice preparations including the SNr to observe drug-induced pathological firing by using drugs that most likely produce it, DA-receptor antagonists (SCH23390 plus sulpiride), to compare with firing patterns found in DA-depleted tissue. The hypothesis is that SNr firing would be similar under both conditions, a prerequisite to the proposal of a similar preparation to test other DIP-producing drugs. Firing was analyzed with three complementary metrics, showing similarities between DA depletion and acute DA-receptor blockade. Moreover, blockade of either nonselective cationic channels or Cav3 T-type calcium channels hyperpolarized the membrane and abolished bursting and irregular firing, silencing SNr neurons in both conditions. Therefore, currents generating firing in control conditions are in part responsible for pathological firing. Haloperidol, a DIP-producing drug, reproduced DA-receptor antagonist firing modifications. Since acute DA-receptor blockade induces SNr neuron firing similar to that found in the 6-hydroxydopamine model of PS, output basal ganglia neurons may play a role in generating DIP. Therefore, this study opens the way to test other DIP-producing drugs. NEW & NOTEWORTHY Dopamine (DA) depletion enhances substantia nigra pars reticulata (SNr) neuron bursting and irregular firing, hallmarks of Parkinsonism. Several drugs, including antipsychotics, antidepressants, and calcium channel antagonists, among others, produce drug-induced Parkinsonism. Here we show the first comparison between SNr neuron firing after DA depletion vs. firing found after acute blockade of DA receptors. It was found that firing in both conditions is similar, implying that pathological SNr neuron firing is also a physiological correlate of drug-induced Parkinsonism.

Bridging Cultures Over-Under: Digital Navigation to Create Liminal Spaces of Possibility

In this paper, we as educators of Indigenous students transitioning into post-secondary education, reflect on our collaborative pilot project: Bridging Cultures Over-Under, a connection of Indigenous students in similar preparation for university programs at the University of Lethbridge in Lethbridge, AB, Canada, and at Batchelor Institute in Darwin, NT, AU. Unbeknownst to the students, the story of attempted assimilation of Indigenous peoples in both countries, and the resultant socio-economic conditions, is both parallel and similar. Through Skype sessions, Indigenous students in polar opposite countries shared their own experiences, culture, history, stories, dreams and desires and some of their academic work. The goal was to understand their shared experience and further build on these relationships so they might learn from and support each other through peer mentoring. Outcomes of this project have lead to a continued connection and the development of a secure Facebook site so that the students can further build their relationships and develop a more extensive network as they continue on their academic journey.

The influence of suspended nanoparticles on the Frederiks threshold of the nematic host

In recent years, several papers reported an enhanced dielectric anisotropy when ferroelectric particles were suspended in a liquid crystal. These results seem to be sensitive to the liquid crystal used and the preparation method of the ferroelectric particles. In this paper, we compare different preparation methods of suspended barium titanate in two different liquid crystal hosts. As a control experiment, we followed similar preparation steps with non-ferroelectric silica particles. In all cases, we found a broadening of the optical Frederiks transition but no change in the dielectric anisotropy. Raman spectroscopy has been used to investigate the loss of tetragonal structure in the barium titanate as a function of milling time and particle size. As reported in the earlier literature, barium titanate does not exhibit a well-defined tetragonal crystal structure below a certain particle size and loses its ferroelectric features. This provides a simple rationalization for the absence of any dielectric enhancement.

Soft Magnetic Properties of the Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4/PVA Composite Film

The Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4/PVA composite film was fabricated by the spin-coating process. To improve the dispersibility and compatibility of Zn0.5Ni0.5Fe2O4nanopaticles, Bis (P, P-bis-ethylhexyl diphosphato) ethanediolato titanate was used as the surface modifier to deal with Zn0.5Ni0.5Fe2O4nanoparticles. The micro morphology and magnetic properties of the composites was observed respectively by 3D Measuring Laser Microscope OLS4000 and MATS type auto test system of magnetic materials. Several contrast groups using by the similar preparation process showed that surface modification on the Zn0.5Ni0.5Fe2O4nanoparticles did not only improve the dispersibility of Fe76Si9B10P5amorphous alloy particles presenting in the PVA, but also improve the softmagnetic properties of the composite films; the magnetic properties of the composite film containing Zn0.5Ni0.5Fe2O4nanoparticles performed better than the one that not contain Zn0.5Ni0.5Fe2O4nanoparticles; the permeability of the film increased with the increasing of the contents of Fe76Si9B10P5amorphous alloy powder in the composites.

Survivability ofVibrio choleraeO1 in Cooked Rice, Coffee, and Tea

This study aimed to investigate the survival ofVibrio choleraeO1 in 3 types of preparation for cooked rice,Oryza sativaL., (plain rice, rice with coconut milk, and rice with ginger); coffee,Coffea canephora, (plain coffee, coffee with sugar, and coffee with sweetened condensed milk); and tea,Camellia sinensis, (plain tea, tea with sugar, and tea with sweetened condensed milk) held at room temperature (27°C). The survival ofV. choleraeO1 was determined by spread plate method on TCBS agar. Initial cultures of 8.00 log CFU/mL were inoculated into each food sample. After 6 h incubation, significant growth was only detected in rice with coconut milk (9.67 log CFU/mL;P<0.05). However, all 3 types of rice preparation showed significant growth ofV. choleraeafter 24 h (P<0.05). For coffee and tea preparations,V. choleraesurvived up to 6 h in tea with condensed milk (4.72 log CFU/mL) but not in similar preparation of coffee. This study showed evidence for the survivability ofV. choleraein rice, coffee, and tea. Thus, holding these food and beverages for an extended period of time at room temperature should be avoided.