Exploring the police use of force continuum with a partial proportional odds model

PurposeThe present study examines a range of police force on the continuum (firearms, TASER/chemical spray and physical force) to see whether they are associated with individual (subject and officer), situational and/or neighborhood factors.Design/methodology/approachA partial proportional odds model is used to analyze police use of force data from 2003 to 2016 in Dallas. Independent variables are allowed for varying effects across the different cumulative dichotomizations of the dependent variable (firearms vs TASER/chemical spray and physical force and firearms and TASER/chemical spray vs physical force).FindingsMost officer demographic and situational factors are consistently significant across the cumulative dichotomizations of police force. In addition, suspect race/ethnicity (Hispanic) and violent crime rates play significant roles when officers make decisions to use firearms, as opposed to TASER/chemical spray and physical force. Overall, situational variables (subject gun possession and contact types) play greater roles than other variables in affecting police use of force.Originality/valueDespite the large body of police use of force research, little to no research has used the partial proportional odds model to examine the ordinal nature of police force from physical to intermediate to deadly force. The current findings can provide important implications for policy and research.

Synthesis of ZnO thin film by chemical spray pyrolysis using its nano powder

The deposition of metal oxides powder faces several problems, including poor adhesion to the bases deposited on them, the presence of many cracks, poor thickness control, and other disadvantages. The current study gives a new and simple idea to deposit thin films using two ZnO powders with nano and microparticle sizes on glass substrates. This was done by transforming the powders to Zinc acetate and then using chemical spray pyrolysis to deposit ZnO thin films. Scanning electron microscope (SEM) images showed that the prepared film from the nanopowder (ZnONano) lost the independence of powder’s nanoparticles and became a homogeneous film with nano projections. But the deposited one from the micro powder (ZnOMicro) had both nanorods and nanoplates. The different shapes and sizes of ZnO particles in ZnOMicro powder were disappeared after the Spray process. The two deposited films were homogeneous, crack-free and there were controllable thicknesses during the deposition. X-ray spectroscopy (EDS) was used to measure weights and atomic percentages of elements for the deposited films. The structures of the deposited films were approximately identical as the X-ray diffraction (XRD) technique showed. The optical properties of these two films were studied and their parameters were measured and calculated.

A modeling study on utilizing low temperature sprayed In2S3 as the buffer layer of CuBaSn(S, Se) solar cells

This study represents the investigation of In2S3 thin films as an electron transport layer in the CuBaSn(S, Se)-CBT(S, Se) solar cells, which have been deposited using the Chemical Spray Pyrolysis method. For studying the electrical properties of films such as conduction and valence band, carrier densities, Fermi level, flat band potential, and semiconductor type, the Mott–Schottky analysis has been used. UV–VIS, XRD, and FESEM have been applied to investigate the optical properties of the layers and the layer’s morphologies. The experimental CBT(S, Se) solar cell has been simulated and validated as the next step. After that, the In2S3 layer has been used as the electron transport layer. The results represent that the In2S3 layer is a suitable substitution for toxic CdS. Finally, the In2S3 properties are varied in reasonable ranges, which means different electron transport layers are screened.

SYNTHESIS AND CHARACTERIZATION OF NANOCRYSTALLINE Co-DOPED ZnO THIN FILMS PREPARED BY CHEMICAL SPRAY PYROLYSIS FOR OPTOELECTRONIC APPLICATIONS

ZnO:Co thin films were synthesized by the chemical spray pyrolysis (CSP) on glass substrates. Then, investigated the impact of Co doping concentration on its physical properties. XRD analyses show that all films have a polycrystalline structure of hexagonal ZnO. The crystallite size increased from 18[Formula: see text]nm to 25[Formula: see text]nm with Co doping concentrations. Furthermore, the unit cell volume increased from 47.485[Formula: see text]Å to 47.831[Formula: see text]Å, and the Zn–O bond length expanded from 1.97588[Formula: see text]Å to 1.98071[Formula: see text]Å. SEM observations reveal the formation of fiber-like nanostructures in the Co-doped thin films. The diameter of nanofibers increased with Co doping concentration from 260[Formula: see text]nm to 700[Formula: see text]nm. The optical characteristics were studied by the UV-Visible spectrophotometer and manifest the optical transparency vary with Co doping. In addition, the band gap decreases from 3.27[Formula: see text]eV to 2.73[Formula: see text]eV with increasing Co doping concentrations. The conductivity varied from 3.35[Formula: see text]S[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] to 19.88[Formula: see text]S[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] with Co doping concentrations. Empirical models were proposed to evaluate the correlated variables with excellent accuracy with the experimental data. The best result was accomplished in ZnO:Co1% films, where good transparency and high conductivity were achieved.

Regularity in distribution, and control, of pests in the hall of mental cultivation, the Forbidden City, Beijing, China

Pests can seriously threaten the safety of organic relics and historic buildings. Every year, the Palace Museum spends a large of money and time preventing and controlling pests, but there is still no a better systematic and targeted method. The Hall of Mental Cultivation is a representative and essential building in the Forbidden City. Through three years of pest monitoring, the species, quantity, and occurrence regularity of the major pests were investigated. During this time, more than ten species of insects were trapped. These included carpet beetles (Anthrenus picturatus hintoni Mroczkowski, 1952 and Thylodrias contractus Motschulsky, 1839), silverfish (Ctenolepisma longicaudata Escherich, 1905), powder-post beetles (Lyctus brunneus Stephens, 1830), booklice (Liposcelis bostrychophila Badonnel, 1931), spider beetles (Ptinus japonicus Reitter, 1877 and Gibbium aequinoctiale Boieldieu, 1865) and the case bearing clothes moths (Tinea pellionella Linnaeus, 1758), among which the Anthrenus picturatus was the primary pests. Abundant resources of organic relics, suitable temperature, humidity, and light environment, and cypress existence are favorable factors for the occurrence of pests, and analysis of these factors is helpful for further integrated pest management (IPM). The period with the most significant number of active pests in the Hall of Mental Cultivation is July and August, and April and May are the rapid growth period. Carpet beetles are the key pests that can affect the overall change trend significantly. It should combine with their living habits, the ideal treatment time and methods, to give them a better control. Fumigation should be done in July and August, while chemical spray should be done referring to the florescence of outdoor trees (March to June), and used of pheromone is reasonable preventative measures.