Geri dönüştürülmüş al-si pistonlarda mikroyapılarının aşınma etkisi

Wear has a tendency of initiating adverse conditions in an automobile engine system. The piston is an important engine component which withstands severe thermal stresses in an engine. Scrap pistons which constitute environmental nuisance will be recycled. A reduced value of wear rate of the pistons determined to be 1.15µg/m was noticed to have an improved microstructure which retains toughness and hardness required for optimal working condition. While wear rate high value of 6.04µg/m yielded micrograph of pistons which produced less pronounced needle shaped eutectic silicon paricles. The micrographs of the aluminium alloy cast piston produced from scraps generator pistons. The result shows primary α-aluminium particles at the background of the structural matrix of the piston alloy. Also, needle shaped near eutectic silicon particles are noticed to be dispersed in the microstructure of the imported piston alloys.Aşınma, bir otomobil motor sisteminde olumsuz koşulları başlatma eğilimindedir. Piston, bir motordaki şiddetli termal gerilimlere dayanan önemli bir motor bileşenidir. Çevresel rahatsızlık oluşturan hurda pistonlar geri dönüştürülecek. 1,15 µg / m olarak belirlenen pistonların aşınma oranının azaltılmış bir değerinin, optimum çalışma koşulu için gerekli olan tokluğu ve sertliği koruyan gelişmiş bir mikro yapıya sahip olduğu fark edilmiştir. 6.04 µg / m'lik yüksek aşınma hızı değeri, daha az belirgin iğne şeklinde ötektik silikon parçacıklar üreten pistonların mikrografını vermiştir. Hurda jeneratör pistonlarından üretilen alüminyum alaşımlı döküm pistonun mikrografları. Sonuçlar piston alaşımının yapısal matrisinin arka planında birincil a-alüminyum parçacıklarını göstermektedir. Ayrıca, ötektik silikon partiküllerine yakın iğne şeklindeki partiküllerin ithal edilen piston alaşımlarının mikroyapısında dağıldığı fark edilir

Crystallography, magnetic susceptibility, heat capacity, and electrical resistivity of heavy fermion LiV2_2O4_4 single crystals grown using a self-flux technique

Magnetically pure spinel compound ${\rm LiV_2O_4}$ is a rare $d$-electron heavy fermion. Measurements on single crystals are needed to clarify the mechanism for the heavy fermion behavior in the pure material. In addition, it is known that small concentrations ($< 1$ mol%) of magnetic defects in the structure strongly affect the properties, and measurements on single crystals containing magnetic defects would help to understand the latter behaviors. Herein, we report flux growth of ${\rm LiV_2O_4}$ and preliminary measurements to help resolve these questions. The magnetic susceptibility of some as-grown crystals show a Curie-like upturn at low temperatures, showing the presence of magnetic defects within the spinel structure. The magnetic defects could be removed in some of the crystals by annealing them at 700 $^\circ$C\@. A very high specific heat coefficient $\gamma$ = 450 mJ/(mol K${^2}$\@) was obtained at a temperature of 1.8 K for a crystal containing a magnetic defect concentration $n$${\rm_{defect}}$ = 0.5 mol%. A crystal with $n$${\rm _{defect}}$ = 0.01 mol% showed a residual resistivity ratio of 50.Comment: 6 pages, 7 figures, Title modifie

1,5-Anhydro-3,6-di-O-benzyl-2-de­oxy-1,2-C-dichloro­methyl­ene-d-glycero-d-gulo-hexitol

In the title compound, C21H22Cl2O4, the pyranosyl ring adopts a twist-boat conformation with the O-benzyl groups in equatorial positions. In the crystal, O—H⋯O hydrogen bonding results in infinite chains of mol­ecules along [100]. The structure is further consolidated by weak C—H⋯O, C—H⋯Cl and C—H⋯π inter­actions. The absolute structure was determined

Women’s Behavioral Patterns in Domestic Tasks in Western Nigeria: Hazards Forecasting with Neural Network Classifier

Behavioral pattern is the characteristic ways a person acts and has been recognized as a cause of many home accidents (h-accd). This study reviewed the types and prevalence of injuries among women in domestic works and proposes a model using Artificial Neural Network (ANN) function to forecast the safety level of women in domestic duty. The study was conducted in some parts of Western Nigeria among 340 subjects (171 married and 169 unmarried) using questionnaire. SPSS was used for data analysis. The ANN function was developed in MATLAB 2015a using the subjects’ behavioral patterns and the model was used to predict safety in domestic duties (d-duties) among some women. ‘Cuts/laceration’ (40%) and ‘skin contact with hot substance’ (35.6%) were commonly reported. Carelessness (26.5%) and distraction (22.1%) were the main leading factors across the groups. Marital status and h-accd (Chi-square =4.323 and p= .038); ‘hours spent on domestic works’ and ‘the h-accd’ were both significant among other tested groups variables. With the developed ANN function, the results of the MSE was 0.33626 indicating that the function predicted the exact value. The result of the predicted h-accd (safety= -0.5445, hazards= 1.0228) in d-duties of the tested variables with the ANN function, showed a very low level of safety. The article concludes that the developed model is reliable and a recommended ergonomic tool useful in all homes, most especially where women perform most domestic works

Ethyl 4-(2,4-dichloro­phen­yl)-6-(6-meth­oxy-2-naphth­yl)-2-oxocyclo­hex-3-ene-1-carboxyl­ate

In the title compound, C26H22Cl2O4, the cyclo­hexenone ring adopts an approximate half-chair conformation, with two C atoms displaced by −0.485 (6) and 0.218 (6) Å from the plane of the other four ring atoms. The dihedral angles between its four almost coplanar [maximum deviation = 0.006 (2) Å] atoms and the benzene and naphthalene ring systems are 59.26 (13) and 79.94 (9)°, respectively. The dihedral angle between the aromatic rings systems is 77.14 (7)°. A short intra­molecular C—H⋯Cl contact generates an S(6) ring. In the crystal, mol­ecules are linked by C—H⋯O and C—H⋯Cl inter­actions to generate a three-dimensional network

(2E)-1-(3-Bromo­phen­yl)-3-(6-meth­oxy-2-naphth­yl)prop-2-en-1-one

In the title compound, C20H15BrO2, the prop-2-en-1-one fragment is substanti­ally twisted [C—C—C—O = 23.0 (11)°]. The dihedral angle between the benzene and naphthalene rings is 44.28 (13)°. The only possible directional inter­actions in the crystal are weak C—H⋯π contacts, which generate (001) sheets

N,N-Dimethylpyridin-4-aminium 1-phenyl­cyclo­pentane-1-carboxyl­ate monohydrate

The cation of the title salt, C7H11N2 +·C12H13O2 −·H2O, is planar (r.m.s. deviation = 0.0184 Å). In the crystal, the cation, anion and water mol­ecule are linked by O—H⋯O and N—H⋯O hydrogen bonds, forming a chain running along the a axis

Spatio-Temporal Distribution of the Black Rhino (<em>Diceros bicornis L.</em>) in the Midlands Black Rhino Conservancy, Zimbabwe

Geographic Information System (GIS) and Remote Sensing (RS) technologies have many attributes that are beneficial in detecting, mapping, and, monitoring change in Land use/Land cover (LULC). This study used the technology with the aim to evaluate the Spatio -temporal impacts of Land use/Land cover Changes (LULCC) on Black Rhino distribution in Midlands Black Rhino Conservancy (MBRC), Zimbabwe. The study used time series satellite data. Landsat images were downloaded for the month of May at five-year intervals from 2000 to 2020. LULC and Normalized Differences Vegetation Index (NDVI) maps obtained were used in change detection. The images were classified using QGIS software on the maximum likelihood classifier algorithm. Presents and absence data for Black Rhino was used for distribution mapping. Quantum Geographic Information System (QGIS) and, R studio software were used for analysis. Results indicated that, a big percentage cover change was the bare land which increased by over 160%. Woodland decreased by about 46% within the same space of time. LULCC showed a significant positive relationship with black rhino distribution (p = 0.0381). MOLUSCE plugin was used for Prediction of LULCC for the year 2030, results indicated the highest increase in bare land 16.59%

(E)-1-(2,5-Dichloro-3-thien­yl)-3-(3,4-dimeth­oxy­phen­yl)prop-2-en-1-one

In the title compound, C15H12Cl2O3S, the prop-2-en-1-one (enone) fragment is almost planar [C—C—C—O = 2.2 (4)°] and it subtends dihedral angles of 11.9 (2) and 11.0 (2)° with the thio­phene and benzene rings, respectively. The dihedral angle between the aromatic rings is 3.47 (16)°. In the crystal, weak C—H⋯O and C—H⋯Cl inter­actions link the mol­ecules, leading to R 2 2(14), R 2 2(24) and C(11) supra­molecular motifs occurring within the three-dimensional network. Weak aromatic π–π stacking [centroid–centroid separations = 3.6823 (15) and 3.8722 (15) Å] may also help to consolidate the packing