Record Values Research Articles

Financial Record Keeping Practices in Micro and Small Businesses in Tanzania

Despite the importance of financial information on access to credit, growth and sustainability, Micro and Small Businesses (MSBs) in Tanzania hardly keep records. This descriptive study investigated financial record keeping practices in MSBs in Iringa and Kinondoni Municipalities employing a sample of 245 owner managers. Data were collected using a questionnaire. Findings indicated that financial record keeping in MSBs remains a big challenge. Some MSBs occasionally kept records while others did not keep records at all. The most kept records were inventories and purchases rather than sales. Reasons for not keeping records included limited knowledge on the value of record keeping, limited skills, shortage of time, shortage of funds to hire skilled personnel and shortage of facilities such as tables/desks and cabinets to store records. The study established a significant association between record keeping and the performance of MSBs. Yet there were mixed perceptions of MSB owner managers regarding the value of record keeping. The study recommends policy action to enforce financial record keeping and strengthen Business Development Services (BDS) provision. Further studies may consider an experimental design with MSBs in the treatment arm supported to keep financial records, then measure impact over a certain period.

Estimation of Inverse Chen Distribution based on Upper Record Values

Estimation of Inverse Chen Distribution based on Upper Record Values

Analysis of indicators of short recording of heart rate variability in comorbid patients with non-communicable diseases

The issues of clinical significance and possibilities of assessing the indicators of variation pulsometry measurement and spectral analysis of a short recording of heart rate variability are highlighted in the article. This is necessary as an objective justification for the subsequent assessment of the functional state of the body and a comprehensive examination of comorbid patients for non-communicable diseases.The aim of the study was to assess the clinical and diagnostic value of a short recording of heart rate variability in comorbid patients with non-communicable diseases in order to increase the effectiveness of measures for their prevention and treatment in Ukraine by improving their diagnosis and prevention through the introduction of modern science-intensive technologies into medical practice.Material and methods. 174 comorbid patients with non-communicable diseases were examined by registering a short record of variability on the hardware-soft-ware complex Poly-Spectrum (Neurosoft, Russia) and the analysis of the results was done. The patients were divided into three groups depending on the degree of comorbidity.Results. Significant differences in spectral analysis and variation pulsometry measurements were established in patients with non-communicable diseases, depending on the degree of comorbidity.Conclusions. The expediency of using the method of short recording of heart rate variability in a comprehensive examination of comorbid patients has been established. The indicator of the total spectral power of the heart rate can be recommended for use as an additional independent predictor of the severity of comorbid pathology and assessment of the functional state.

Unlocking Higher Power Efficiencies in Luminescent Solar Concentrators through Anisotropic Luminophore Emission.

The luminescent solar concentrator (LSC) offers a potential pathway for achieving low-cost, fixed-tilt light concentration. Despite decades of research, conversion efficiency for LSC modules has fallen far short of that achievable by geometric concentrators. However, recent advances in anisotropically emitting nanophotonic structures could enable a significant step forward in efficiency. Here, we employ Monte Carlo ray-trace modeling to evaluate the conversion efficiency for anisotropic luminophore emission as a function of photoluminescence quantum yield, waveguide concentration, and geometric gain. By spanning the full LSC parameter space, we define a roadmap toward high conversion efficiency. An analytical function is derived for the dark radiative current of an LSC to calculate the conversion efficiency from the ray-tracing results. We show that luminescent concentrator conversion efficiency can be increased from the current record value of 7.1-9.6% by incorporating anisotropy. We provide design parameters for optimized luminescent solar concentrators with practical geometrical gains of 10. Using luminophores with strongly anisotropic emission and high (99%) quantum yield, we conclude that conversion efficiencies beyond 28% are achievable. This analysis reveals that for high LSC performance, waveguide losses are as important as the luminophore quantum yield.

The September 2020 Wildfires over the Pacific Northwest

AbstractA series of major fires spread across eastern Washington and western Oregon starting on September 7, 2020, driven by strong easterly and northeasterly winds gusting to ~70 kt at exposed locations. This event was associated with a high-amplitude upper-level ridge over the eastern Pacific and a mobile trough that moved southward on its eastern flank. The synoptic environment during the event was highly unusual, with the easterly 925-hPa wind speeds at Salem, Oregon, being unprecedented for the August-September period. The September 2020 wildfires produced dense smoke that initially moved westward over the Willamette Valley and eventually covered the region. As a result, air quality rapidly degraded to hazardous levels, representing the worst air quality period of recent decades. High-resolution numerical simulations using the WRF model indicated the importance of a high-amplitude mountain wave in producing strong easterly winds over western Oregon.The dead fuel moisture levels over eastern Washington before the fires were typical for that time of the year. Along the western slopes of the Oregon Cascades, where the fuels are largely comprised of a dense conifer forest with understory vegetation, fire weather indices were lower (moister) than normal during the early part of the summer, but transitioned to above-normal (drier) values during August, with a spike to record values in early September coincident with the strong easterly winds.Forecast guidance was highly accurate for both the Washington and Oregon wildfire events. Analyses of climatological data and fuel indices did not suggest that unusual pre-existing climatic conditions were major drivers of the September 2020 Northwest wildfires.

Demonstration of reduced neoclassical energy transport in Wendelstein 7-X

Research on magnetic confinement of high-temperature plasmas has the ultimate goal of harnessing nuclear fusion for the production of electricity. Although the tokamak1 is the leading toroidal magnetic-confinement concept, it is not without shortcomings and the fusion community has therefore also pursued alternative concepts such as the stellarator. Unlike axisymmetric tokamaks, stellarators possess a three-dimensional (3D) magnetic field geometry. The availability of this additional dimension opens up an extensive configuration space for computational optimization of both the field geometry itself and the current-carrying coils that produce it. Such an optimization was undertaken in designing Wendelstein 7-X (W7-X)2, a large helical-axis advanced stellarator (HELIAS), which began operation in 2015 at Greifswald, Germany. A major drawback of 3D magnetic field geometry, however, is that it introduces a strong temperature dependence into the stellarator’s non-turbulent ‘neoclassical’ energy transport. Indeed, such energy losses will become prohibitive in high-temperature reactor plasmas unless a strong reduction of the geometrical factor associated with this transport can be achieved; such a reduction was therefore a principal goal of the design of W7-X. In spite of the modest heating power currently available, W7-X has already been able to achieve high-temperature plasma conditions during its 2017 and 2018 experimental campaigns, producing record values of the fusion triple product for such stellarator plasmas3,4. The triple product of plasma density, ion temperature and energy confinement time is used in fusion research as a figure of merit, as it must attain a certain threshold value before net-energy-producing operation of a reactor becomes possible1,5. Here we demonstrate that such record values provide evidence for reduced neoclassical energy transport in W7-X, as the plasma profiles that produced these results could not have been obtained in stellarators lacking a comparably high level of neoclassical optimization.

PREDICTORS OF SCHOOL CHOICE: THE CASE OF PARENTS IN CAPE COAST, GHANA

<div>We identified the pertinent factors affecting parents’ choice of a particular senior high school (SHS) in Ghana, focusing on parents with at least one child in a SHS in Ghana and are residents of Cape Coast. The approach and design used were quantitative and descriptive survey design respectively. A sample of 637 of the parents, made up of 349 women and 288 men, was used. The parents were selected using convenience and snowball sampling techniques. A questionnaire, with a reliability coefficient ranging from 0.735 – 0.829, was the instrument used to collect the data. Out of the 637 parents sampled, we were able to retrieve 588 completed questionnaires, representing 92.3 percent response rate. The data were analysed using cross tabulation and linear multiple regression analysis. The findings revealed that parents preferred public boarding SHS which is single-sex education. Also, parents preferred schools with excellent academic record, quality instruction, and positive school values. Similarly, family/parental related factors such as family moral and religious values, and parents’ income and education levels, and also social related factors such as school popularity and brand, peer influence, and social network predict significantly and positively parents’ choice of a particular SHS. We conclude that school, family and social related factors are able to influence parents’ school choice. It is recommended to heads of SHSs to be attentive to the various institutional factors and create schools that address the needs of the parents in their communities in order to attract and retain students.</div><div> </div><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0889/a.php" alt="Hit counter" /></p>

High performance temperature difference triboelectric nanogenerator

Usually, high temperature decreases the output performance of triboelectric nanogenerator because of the dissipation of triboelectric charges through the thermionic emission. Here, a temperature difference triboelectric nanogenerator is designed and fabricated to enhance the electrical output performance in high temperature environment. As the hotter friction layer’s temperature of nanogenerator is 0 K to 145 K higher than the cooler part’s temperature, the output voltage, current, surface charge density and output power are increased 2.7, 2.2, 3.0 and 2.9 times, respectively (from 315 V, 9.1 μA, 19.6 μC m−2, 69 μW to 858 V, 20 μA, 58.8 μC m−2, 206.7 μW). With the further increase of temperature difference from 145 K to 219 K, the surface charge density and output performance gradually decrease. At the optimal temperature difference (145 K), the largest output current density is 443 μA cm−2, which is 26.6% larger than the reported record value (350 μA cm−2).

Green Conversion of CO2 and Propargylamines Triggered by Triply Synergistic Catalytic Effects in Metal-Organic Frameworks.

Cyclization of propargylamines with CO2 to obtain 2-oxazolidone heterocyclic compounds is an essential reaction in industry but it is usually catalyzed by noble-metal catalysts with organic bases as co-catalysts under harsh conditions. We have synthesized a unique CuI /CuII mixed valence copper-based framework {[(CuI 6 I5 )Cu3 II L6 (DMA)3 ](NO3 )⋅9DMA}n (1) with good solvent and thermal stability, as well as a high density of uncoordinated amino groups evenly distributed in the large nanoscopic channels. Catalytic experiments show that 1 can effectively catalyze the reaction of propargylamines with CO2 , and the yield can reach 99 %. The turnover frequency (TOF) reaches a record value of 230 h-1 , which is much higher than that of reported noble-metal catalysts. Importantly, this is the first report of heterogeneously catalyzed green conversion of propargylamines with CO2 without solvents and co-catalysts under low temperature and atmospheric pressure. A mechanistic study reveals that a triply synergistic catalytic effect between CuI /CuII and uncoordinated amino groups promotes highly efficient and green conversion of CO2 . Furthermore, 1 directly catalyzes this reaction with high efficiency when using simulated flue gas as a CO2 source.

Green Conversion of CO2 and Propargylamines Triggered by Triply Synergistic Catalytic Effects in Metal–Organic Frameworks

AbstractCyclization of propargylamines with CO2 to obtain 2‐oxazolidone heterocyclic compounds is an essential reaction in industry but it is usually catalyzed by noble‐metal catalysts with organic bases as co‐catalysts under harsh conditions. We have synthesized a unique CuI/CuII mixed valence copper‐based framework {[(CuI6I5)Cu3IIL6(DMA)3](NO3)⋅9DMA}n (1) with good solvent and thermal stability, as well as a high density of uncoordinated amino groups evenly distributed in the large nanoscopic channels. Catalytic experiments show that 1 can effectively catalyze the reaction of propargylamines with CO2, and the yield can reach 99 %. The turnover frequency (TOF) reaches a record value of 230 h−1, which is much higher than that of reported noble‐metal catalysts. Importantly, this is the first report of heterogeneously catalyzed green conversion of propargylamines with CO2 without solvents and co‐catalysts under low temperature and atmospheric pressure. A mechanistic study reveals that a triply synergistic catalytic effect between CuI/CuII and uncoordinated amino groups promotes highly efficient and green conversion of CO2. Furthermore, 1 directly catalyzes this reaction with high efficiency when using simulated flue gas as a CO2 source.

Interval estimation of multicomponent stress–strength reliability based on inverse Weibull distribution

This paper considers interval estimation of stress–strength reliability of k-out-of-n system when the stress and strength components follow inverse Weibull distributions. Besides the asymptotic and bootstrap confidence intervals, we derive HPD credible intervals when the shape parameter is known or unknown. We also propose the pivotal quantity and generalized confidence interval of reliability. We study the estimation of multicomponent stress–strength reliability using lower record values. Generalized, asymptotic, and bootstrap confidence intervals are derived using lower record values. We also derive confidence intervals of multicomponent stress–strength reliability assuming the shape parameters are different. We propose HPD credible intervals, generalized and bootstrap confidence intervals. Monte Carlo simulation is performed to compare the confidence intervals. Real data examples are presented to demonstrate the practicability of the confidence intervals.

On numbers of observations in random regions determined by records for tail-less populations

In this paper we study the number of observations that occur between successive record times and fall into a random region determined by a current record value and a given Borel set. We describe the asymptotic behavior of this random number in the case when the population is tail-less.

Roll‐to‐Roll Processes for the Fabrication of Perovskite Solar Cells under Ambient Conditions

Recent progress in the engineering and fabrication optimization of hybrid perovskite solar cells (PSCs) has led to power conversion efficiencies (PCEs) of up to 25.2%. The properties of perovskite solutions enable low‐temperature, scalable coating methods that are compatible with the roll‐to‐roll (R2R) fabrication process. Despite this, there is still a significant lag in efficiency in large‐area devices fabricated using the R2R process, which achieves PCEs of 50% of the record value. Direct translation of research results to large‐scale commercially acceptable levels is crucial for commercialization, along with long‐term durability and processing reproducibility of the different device layers. Herein, the recent progress of several coating and R2R processes for the formation of PSC layers, detailing the key variables involved in the process, with an emphasis on the nucleation and crystallization of the perovskite film, is considered. The barriers and challenges in producing high‐quality perovskite films and improving the stability of devices are discussed. In addition, stability protocols for PSCs are discussed as they are key to unifying PSC stability and performance assessment, which is required to gain a better understanding of the different compounds and layers used in cell fabrication and the approaches necessary for their optimization.

Notes on Entropy for Concomitants of Record Values in Farlie-Gumbel-Morgenstern (FGM) Family

Let {(Xi , Yi), i ≥ 1} be a sequence of bivariate random variables from a continuous distribution. If {Rn, n ≥ 1} is the sequence of record values in the sequence of X’s, then the Y which corresponds with the nth record will be called the concomitant of the nth-record, denoted by R[n] . In FGM family, we determine the amount of information contained in R[n] and compare it with amount of information given in Rn. Also, we show that the Kullback-Leibler distance among the concomitants of record values is distribution-free. Finally, we provide some numerical results of mutual information and Pearson correlation coefficient for measuring the amount of dependency between Rn and R[n] in the copula model of FGM family.

Recent results of fusion triple product on EAST tokamak

High fusion triple product has been obtained in the advanced scenarios with high normalized beta (β N) on the Experimental Advanced Superconducting Tokamak (EAST). A record value of n i0 T i0 τ E ∼ 1.0 × 1019 m−3 keV s for EAST deuterium plasma has been achieved, which is due to the formation of strong and broad internal transport barriers (ITBs) in n e, T e and T i profiles. Analysis shows that the strong ITB formation could be attributed to the reduction of transport from ITG modes. Based on the analysis, the physical mechanisms and methods to further improve the plasma performance are discussed.

Alkalis-doping of mixed tin-lead perovskites for efficient near-infrared light-emitting diodes

Substitution of lead (Pb) with tin (Sn) is a very important way to reduce the bandgap of metal halide perovskite for applications in solar cells, and near infrared (NIR) light-emitting diodes (LEDs), etc. However, mixed Pb/Sn perovskite becomes very disordered with high trap density when the Sn molar ratio is less than 20%. This limits the applications of mixed Pb/Sn perovskites in optoelectronic devices such as wavelength tunable NIR perovskite LEDs (PeLEDs). In this work, we demonstrate that alkali cations doping can release the microstrain and passivate the traps in mixed Pb/Sn perovskites with Sn molar ratios of less than 20%, leading to higher carrier lifetime and photoluminescence quantum yield (PLQY). The external quantum efficiency (EQE) of Sn0.2Pb0.8-based NIR PeLEDs is dramatically enhanced from 0.1% to a record value of 9.6% (emission wavelength: 868 nm). This work provides a way of making high quality mixed Pb/Sn optoelectronic devices with small Sn molar ratios.

Lignin-Based Gel Polymer Electrolyte for Cationic Conductivity.

The article presents the results of the preparation and study of a gel-polymer electrolyte based on lignin obtained from Pinus sylvestris. Sulfonation and subsequent chlorination of lignin make possible implementation of the principle of mono-ionic conductivity in a natural biopolymer matrix, which provides predominantly cationic conductivity of the electrolyte. Based on the results of the qualitative and quantitative analysis of the synthesized samples, the mechanisms of the chemical conversion of the biopolymer, the structure models of the converted fragments of macromolecules, as well as the quantum-chemical calculation of their electronic and geometric parameters are presented. The key electronic characteristics of the gel polymer electrolytes (GPE) based on a composite of lignins with 20 wt.% polyvinyl alcohol are determined by impedance spectroscopy. The maximum value of the specific volume conductivity is 2.48 × 10−4 S cm−1, which is comparable with most commercial electrolytes of this type, but at the same time, record values are reached in the number of lithium cation transfer of 0.89. The studies allow to identify the basic laws of the effect of chemical modification on the structure of GPE and describe the mechanism of ionic conductivity.

Moment properties of lower record values from generalized inverse Weibull distribution and characterization

In this paper, the exact expressions as well as recurrence relations for single and product moments of the generalized lower record values from generalized inverse Weibull distribution are obtained. Further, the characterization of the given distribution is carried out through recurrence relations and conditional moment.

Industrial Protection System using Arduino and IoT

The Industrial protection system designed using Arduino and IOT mainly focuses on the protection of industries from various losses occurring due to accidents caused due to improper conditions and maintenance. Gas leaks can cause fires that cause huge industrial losses; Instant fire detection is also required in the event of a furnace explosion or other conditions. Additionally, poor lighting in industries can create unsuitable working conditions, increasing the likelihood of accidents. The system uses Arduino to achieve this functionality. The system uses temperature sensors in combination with gas light sensors to detect fires, gas leaks, and low light to prevent industrial accidents and avoid leaks. These setups also work as an anti-theft security system where it utilizes the IR sensor to detect the objects coming in its path. So this IR sensor works with the help of direct incidence of radiation on the photodiode. This IR LED which is placed on one side of the board and the photodiode is placed on the other helps to detect any obstacle or object which comes closer to contact with it. This object detection is indicated with the help of an alarm to notify us. The system consists of light, gas, and temperature sensors interconnected with Arduino and LCD screens. Sensor data is constantly scanned to record values and check for fire, gas leaks, or poor lighting, and then this data is transmitted online. The Wi-fi module is used to achieve internet functionality. The Blynk server then displays this information online, to achieve the desired result.

Inferences for generalized Topp-Leone distribution under dual generalized order statistics with applications to Engineering and COVID-19 data

This article accentuates the estimation of a two-parameter generalized Topp-Leone distribution using dual generalized order statistics (dgos). In the part of estimation, we obtain maximum likelihood (ML) estimates and approximate confidence intervals of the model parameters using dgos, in particular, based on order statistics and lower record values. The Bayes estimate is derived with respect to a squared error loss function using gamma priors. The highest posterior density credible interval is computed based on the MH algorithm. Furthermore, the explicit expressions for single and product moments of dgos from this distribution are also derived. Based on order statistics and lower records, a simulation study is carried out to check the efficiency of these estimators. Two real life data sets, one is for order statistics and another is for lower record values have been analyzed to demonstrate how the proposed methods may work in practice.