scholarly journals The Relationship between Surface and In-Depth Hardness for the Nitrocarburizing Treatment Process

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 812
Author(s):  
Mihály Réger ◽  
Richárd Horváth ◽  
Attila Széll ◽  
Tamás Réti ◽  
Viktor Gonda ◽  
...  
Keyword(s):  
Surface Layer ◽  
Surface Hardness ◽  
Case Depth ◽  
Hardness Distribution ◽  
Cross Sectional ◽  
Metallographic Examination ◽  
Indirect Information ◽  
The Mathematical Model ◽  
The Relationship ◽  
Hardness Values

The aim of this study is to exhibit the mutual connection between surface and in depth hardness values in the case of surface-treated metal samples with inhomogeneous hardness distribution in the surface layer. The reason for surface treatments of metal alloys is most commonly to increase the hardness and wear resistance at the surface. Case depth, as a result of surface treatment and the in-depth hardness distribution, can be determined by measuring the hardness of a section perpendicular to the treated surface and by metallographic examination. The result of heat treatment can also be checked rapidly by surface hardness testing. Surface hardness carries only indirect information regarding case depth and hardness distribution. Surface and cross-sectional hardness can be related to the mathematical modeling of the plastic zone developing in the indentation process. The mathematical model applied in this study allows the conversion of the surface hardness function into the in-depth hardness function and vice-versa. The calculation method presented was validated by analyzing the hardness data of nitrocarburized samples of various case depths. The validation result proves that cross-sectional hardness distribution can be adequately estimated by surface hardness data in the case of a surface layer with monotonically decreasing hardness distribution.

scholarly journals METHODS OF FORMULATING AND SOLVING OPTIMIZATION PROBLEMS OF CUTTING LOGS OF LARGE SIZE BY BAR-SAWING METHOD WITH CUTTING OUT ONE BAR AND FIVE PAIRS OF SIDE EDGING BOARDS WITH SUBSEQUENT SAWING LUMBER FOR EDGED BOARDS

2017 ◽  
Vol 7 (1) ◽  
pp. 137-150
Author(s):  
Агапов ◽  
Aleksandr Agapov
Keyword(s):  
Mathematical Model ◽  
Objective Function ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Target Function ◽  
Cross Sectional ◽  
Optimization Task ◽  
Cutting Out ◽  
The Mathematical Model ◽  
The Relationship

For the first time the mathematical model of task optimization for this scheme of cutting logs, including the objective function and six equations of connection. The article discusses Pythagorean area of the logs. Therefore, the target function is represented as the sum of the cross-sectional areas of edging boards. Equation of the relationship represents the relationship of the diameter of the logs in the vertex end with the size of the resulting edging boards. This relationship is described through the use of the Pythagorean Theorem. Such a representation of the mathematical model of optimization task is considered a classic one. However, the solution of this mathematical model by the classic method is proved to be problematic. For the solution of the mathematical model we used the method of Lagrange multipliers. Solution algorithm to determine the optimal dimensions of the beams and side edging boards taking into account the width of cut is suggested. Using a numerical method, optimal dimensions of the beams and planks are determined, in which the objective function takes the maximum value. It turned out that with the increase of the width of the cut, thickness of the beam increases and the dimensions of the side edging boards reduce. Dimensions of the extreme side planks to increase the width of cut is reduced to a greater extent than the side boards, which are located closer to the center of the log. The algorithm for solving the optimization problem is recommended to use for calculation and preparation of sawing schedule in the design and operation of sawmill lines for timber production. When using the proposed algorithm for solving the optimization problem the output of lumber can be increased to 3-5 %.

scholarly journals A Study Surface Layer and Hardness Produced by Induction Hardened S45C Steel

2014 ◽  
Vol 664 ◽  
pp. 43-47 ◽  
Author(s):  
Alain Kusmoko ◽  
Rosfian Arsyah Dahar ◽  
Hui Jun Li ◽  
Syamsul Hadi
Keyword(s):  
Surface Layer ◽  
Internal Stress ◽  
Induction Heating ◽  
Retained Austenite ◽  
Surface Hardness ◽  
Case Depth ◽  
Chemical Compositions ◽  
Different Temperatures ◽  
Significant Case ◽  
Cooling Speed

A cylinder of Carbon Steel S45C with a ferrite and pearlite structure was analysed to improve the hardness and surface layer as well as the toughness. Accordingly, it is important to undertake a heat treatment process for the hardness and surface layer of this steel. The heat teatment process was carried out using induction heating with five different temperatures of 800°C, 900°C, 1000°C, 1100°C and 1200 °C followed by water quenching with certain cooling speed. The chemical compositions and microstructures of these samples were characterized by spectrometer and optical microscopy. The microhardness of the samples was measured and the surface treatment of the samples was examined using an induction heating furnace. The results showed significant case depth and surface hardness as well as microstructure with martensite and retained austenite that is hard and brittle because of internal stress. Further, to reduce the amount of retained austenite and internal stress, it is necessary to carry out tempering of 300°C, 500°C and 700°C in order to produce toughness of the steel with slightly reduce in hardness.

IMPROVEMENT OF WEAR RESISTANCE OF SHREDDER BLADES USED IN A REFUSE-DERIVED FUEL (RDF) FACILITY BY PLASMA NITRIDING

2019 ◽  
Vol 27 (04) ◽  
pp. 1950131
Author(s):  
HAKAN AYDIN ◽  
FURKAN BOSTANCI
Keyword(s):  
Wear Resistance ◽  
Working Conditions ◽  
Plasma Nitriding ◽  
Surface Hardness ◽  
Service Condition ◽  
Case Depth ◽  
Nitriding Process ◽  
Nitriding Time ◽  
Refuse Derived Fuel ◽  
Hardness Values

Refuse-derived fuel (RDF) is a kind of renewable energy source to produce energy for replacement of fossil fuels. Aggressive working conditions in RDF facilities cause the shredder blades to wear out quickly. So, the purpose of this paper was to study the effect of plasma-nitriding process on wear resistance of shredder blades made of AISI D2 tool steel in the service condition of RDF facility. Shredder blades were commercially available from two different suppliers (A and B suppliers). These hardened shredder blades were plasma-nitrided in the mixed nitrogen and hydrogen atmosphere at a volume ratio of 3:1 at 450∘C for 12, 18 and 24[Formula: see text]h at a total pressure of 250 Pa. Characterisation of plasma-nitrided layers on the shredder blades was carried out by means of microstructure and microhardness measurements. Wear tests of plasma-nitrided shredder blades were performed under actual working conditions in the RDF facility. Wear analysis of these shredder blades was conducted using three-dimensional (3D) optical measuring instrument GOM ATOS II. The compositional difference of the shredder blades provided by A and B suppliers played an important role on the nitrided layer. The case depth of A-blades significantly increased with increasing plasma-nitriding time. However, the case depth of B-blades was fairly lower at the same nitriding time and only slightly increased with increasing plasma-nitriding time. Plasma-nitriding process significantly improved the surface hardness of the shredder blades. Maximum surface hardness values were achieved at nitriding time of 18 h for both blades. In this case, this increase in surface hardness values was above 100%. At nitriding time of 24[Formula: see text]h, the maximum surface hardness of A-blades significantly decreased, whereas this decrease in surface hardness of B-blades was the negligible value. The wear test results showed that plasma-nitriding process significatly decreased the wear of shredder blades; 18 h nitriding for A-blades and 24[Formula: see text]h nitriding for B-blades had better wear-reducing ability in the service condition of RDF facility. In these cases, the decreases in the total volume wear loss for A- and B-blades were 53% and 60%, respectively.

Microstructure of Electro-Eroded Cemented Carbide Surfaces

1968 ◽  
Vol 26 ◽  
pp. 284-285
Author(s):  
V. N. Filimonenko ◽  
M. H. Richman ◽  
J. Gurland
Keyword(s):  
Surface Layer ◽  
Cobalt Content ◽  
Cemented Carbides ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Metallographic Examination ◽  
Standard Procedures ◽  
Face Centered ◽  
Diamond Paste ◽  
Plastic Carbon

The high temperatures and pressures that are found in a spark gap during electrical discharging lead to a sharp phase transition and structural transformation in the surface layer of cemented carbides containing WC and cobalt. By means of X-ray diffraction both W2C and a high-temperature monocarbide of tungsten (face-centered cubic) were detected after electro-erosion. The W2C forms as a result of the peritectic reaction, WC → W2C+C. The existence and amount of the phases depend on both the energy of the electro-spark discharge and the cobalt content. In the case of a low-energy discharge (i.e. C=0.01μF, V = 300v), WC(f.c.c.) is generally formed in the surface layer. However, at high energies, (e.g. C=30μF, V = 300v), W2C is formed at the surface in preference to the monocarbide. The phase transformations in the surface layer are retarded by the presence of larger percentages of cobalt.Metallographic examination of the electro-eroded surfaces of cemented carbides was carried out on samples with 5-30% cobalt content. The specimens were first metallographically polished using diamond paste and standard procedures and then subjected to various electrical discharges on a Servomet spark machining device. The samples were then repolished and etched in a 3% NH4OH electrolyte at -0.5 amp/cm2. Two stage plastic-carbon replicas were then made and shadowed with chromium at 27°.

Coping Style as a Mediator of the Relationship Between Depressive Symptoms and Deliberate Self-Harm

Crisis ◽  
2011 ◽  
Vol 32 (5) ◽  
pp. 272-279 ◽  
Author(s):  
Allison S. Christian ◽  
Kristen M. McCabe
Keyword(s):  
Depressive Symptoms ◽  
Undergraduate Students ◽  
Cross Sectional Study ◽  
Self Report ◽  
Hierarchical Regression ◽  
Cross Sectional ◽  
Deliberate Self Harm ◽  
Self Blame ◽  
Self Harm ◽  
The Relationship

Background: Deliberate self-harm (DSH) occurs with high frequency among clinical and nonclinical youth populations. Although depression has been consistently linked with the behavior, not all depressed individuals engage in DSH. Aims: The current study examined maladaptive coping strategies (i.e., self-blame, distancing, and self-isolation) as mediators between depression and DSH among undergraduate students. Methods: 202 students from undergraduate psychology courses at a private university in Southern California (77.7% women) completed anonymous self-report measures. Results: A hierarchical regression model found no differences in DSH history across demographic variables. Among coping variables, self-isolation alone was significantly related to DSH. A full meditational model was supported: Depressive symptoms were significantly related to DSH, but adding self-isolation to the model rendered the relationship nonsignificant. Limitations: The cross-sectional study design prevents determination of whether a casual relation exists between self-isolation and DSH, and obscures the direction of that relationship. Conclusions: Results suggest targeting self-isolation as a means of DSH prevention and intervention among nonclinical, youth populations.

Authoritative Maternal Parenting Associates With the Explicit Need for Autonomy

2020 ◽  
Vol 41 (2) ◽  
pp. 110-116
Author(s):  
Jonathan E. Ramsay
Keyword(s):  
University Students ◽  
Parenting Style ◽  
Cross Sectional ◽  
Perceived Parenting ◽  
Maternal Parenting ◽  
Retrospective Design ◽  
Dependent Variables ◽  
Paternal Parenting ◽  
The Relationship

Abstract. Previous research suggests that parenting style influences the development of the needs for achievement, power, and affiliation. The present study investigated the relationship between parenting style and another important motive disposition – the need for autonomy – in a sample of Singapore university students ( N = 97, 69% female), using a cross-sectional and retrospective design. It was predicted that an authoritative perceived parenting style would relate positively to the implicit need for autonomy ( nAut), the explicit need for autonomy ( sanAut), and the congruence between these two motive dispositions. Authoritative maternal parenting was found to positively associate with sanAut, while maternal parenting was not found to associate with nAut, or with nAut/ sanAut congruence. Paternal parenting was not associated with any of the dependent variables.

HUBUNGAN KUALITAS KEHIDUPAN KERJA TERHADAP KINERJA PERAWAT PELAKSANA

2019 ◽  
Vol 9 (4) ◽  
pp. 413-420
Author(s):  
Amella Gusty ◽  
Dachriyanus Dachriyanus ◽  
Leni Merdawati
Keyword(s):  
District Hospital ◽  
Simple Random Sampling ◽  
Work Life ◽  
Quality Of Work Life ◽  
P Value ◽  
Work Context ◽  
Cross Sectional ◽  
Quality Of Work ◽  
The Relationship

Kinerja perawat merupakan hasil yang dicapai dalam melaksanakan asuhan keperawatan di rumah sakit. Terciptanya asuhan keperawatan yang optimal sangat diperlukan dukungan dari pihak rumah sakit salah satunya adalah menciptakan kualitas kehidupan kerja baik bagi perawat. Penelitian ini bertujuan untuk mengetahui hubungan antara kualitas kehidupan kerja terhadap kinerja perawat pelaksana di RSUD Teluk Kuantan. Jenis penelitian kuantitatif dengan pendekatan cross sectional. Jumlah sampel 120 responden yang diperoleh melalui proportionate simple random sampling. Hasil penelitian menunjukkan kualitas kehidupan kerja perawat RSUD Teluk Kuantan berada pada kategori sedang, kinerja perawat berada pada kategori kurang baik. Berdasarkan analisis kedua variabel teridentifikasi bahwa tidak ada hubungan antara kualitas kehidupan kerja dengan kinerja perawat pelaksana dengan  p value 0,817. Dimensi work context merupakan komponen yang memiliki hubungan dengan kinerja perawat pelaksana dengan p value 0,008, dimensi work life  tidak berhubungan secara signifikan dengan kinerja perawat. Kesimpulan penelitian diketahui tidak ada hubungan antara kualitas kehidupan kerja dengan kinerja perawat pelaksana. Ada hubungan dimensi work context dengan kinerja perawat pelaksana. Tidak ada hubungan dimensi work life dengan kinerja perawat.   Kata kunci: kualitas kehidupan kerja, kinerja, perawat pelaksana   THE RELATIONSHIP BETWEEN THE QUALITY OF WORK LIFE AND THE PERFORMANCE OF IMPLEMENTERS NURSES   ABSTRACT Nurse performance is the result achieved in implementing nursing care in a hospital. The creation of optimal nursing care is very much needed support from the hospital, one of which is to create a good quality of work life for nurses. This study aims to determine the relationship between the quality of work life and the performance of nurses at the Kuantan District Hospital. This type of quantitative research with cross sectional approach. The number of samples of 120 respondents obtained through proportionate simple random sampling. The results showed that the quality of work life of nurses at the Kuantan District Hospital was in the medium category, the nurses' performance was in the unfavorable category. Based on the analysis of the two variables, it was identified that there was no relationship between the quality of work life with the performance of implementing nurses with a p value of 0.817. The work context dimension is a component that has a relationship with the performance of nurses implementing with p value 0.008, the dimension of work life does not significantly correlate with nurse performance. The conclusion of the research is that there is no relationship between the quality of work life and the performance of the implementing nurses. There is a relationship between the dimensions of the work context and the performance of the nurses. There is no relationship between the dimensions of work life and nurse performance.   Keywords: quality of work life, performance, implementers nurse

HUBUNGAN KOMUNIKASI TERAPEUTIK PERAWAT DENGAN KECEMASAN ANAK USIA PRASEKOLAH AKIBAT HOSPITALISASI

2019 ◽  
Vol 9 (2) ◽  
pp. 135-140
Author(s):  
Qurrotul Aeni ◽  
Andriyani Mustika Nurwijayanti ◽  
Muhammad Khabib Burhanuddin Iqomh
Keyword(s):  
Research Data ◽  
School Age Children ◽  
P Value ◽  
School Age ◽  
Therapeutic Communication ◽  
Cross Sectional ◽  
Communication Anxiety ◽  
Children’S Anxiety ◽  
The Relationship ◽  
Severe Anxiety

Introduction: anxiety is a condition that will be experienced by children who experience hospitalization and must get attention and management. Anxiety during hospitalization that is not properly addressed will hinder treatment and affect child development. The purpose of the study: to determine the relationship between therapeutic communication nurses and the anxiety of preschool children due to hospitalizationMethod: The study design used descriptive correlation with a cross-sectional approach. The number of samples is 31 with purposive sampling. Collecting research data using a questionnaire.Results: The results showed a majority of therapeutic communication was 61.3%, anxiety in children due to hospitalization of 100% with severe anxiety was 58.1%, there was a relationship between therapeutic communication and children's anxiety (p = 0.001). Suggestions need to be carried out further research on the factors that influence the low therapeutic communication in nurses.Discussion: The results of the statistical analysis using the Spearman's Rho test got p value 0.001 (p <0.05) the relationship between therapeutic communication and the anxiety of pre-school age children who experienced hospitalization, therapeutic communication can be used as an action to prevent anxiety due to hospitalization in pre-school age children.Suggestion: need to do further research on the factors that influence the low therapeutic communication in nurses Keywords: therapeutic communication, anxiety, hospitalization.  

STRATEGI KOPING ORANG TUA TERHADAP ANAK AUTIS DAN POLA ASUH ORANG TUA

2018 ◽  
Vol 11 (2) ◽  
pp. 196-204
Author(s):  
Asirotul Ma’rifah ◽  
Naning Puji Suryantini Suryantini ◽  
Rina Mardiyana
Keyword(s):  
Coping Strategies ◽  
Sampling Technique ◽  
Children With Autism ◽  
Adaptive Coping ◽  
Autistic Children ◽  
Cross Sectional ◽  
Authoritarian Parenting ◽  
Cross Tabulation ◽  
Relationship Of ◽  
The Relationship

Autism is still a nightmare for most parents. Parents with autism can be very stressful when dealing with a hyperactive child's behavior, aggressive and passive. Stress experienced by parents of children with autism will affect the ability of parents in the parenting role, especially in relation to coping strategies have in dealing with problems of children. The participation of parents is crucial the success of socializing with children with autism in the general population. This study aims to determine the relationship of coping strategies parents of autistic children and parenting parents. This type of research is an analytic correlation with cross sectional approach. The population in this study were all parents of autistic children in SLB Muhammadiyah Mojokerto numbering 15 people. Samples in this study were all parents of autistic children in SLB Muhammadiyah Mojokerto which totaled 15 people by using total sampling technique. Collecting data using questionnaires. Data analized use cross tabulation, presented in a frequency distribution. On cross-tabulation obtained results tend to use maladaptive coping strategies permissive parenting that is 8 (53.3%), there are also respondents who use adaptive coping strategies using authoritarian parenting as much as one person (16.7%), and adaptive coping strategies tend using democratic parenting style as much as 5 people (33.3%). Expected parents still seeking information to broaden their parents on coping strategies of parents of autistic children and parenting parents as well as parents to give special attention for children with autism to the development and advancement of their lives because they have the same rights as any other normal child.

IDENTIFIKASI SERTA HUBUNGAN KONSTRUKSI SUMUR GALI TERHADAP KANDUNGAN COLIFORM PADA AIR SUMUR GALI DI DUSUN JIKEN KABUPATEN LOMBOK TIMUR

2019 ◽  
Vol 7 (2) ◽  
pp. 115
Author(s):  
Dini Yuliansari
Keyword(s):  
Cross Sectional Study ◽  
Coliform Bacteria ◽  
Well Water ◽  
Chi Square ◽  
Cross Sectional ◽  
Content Variable ◽  
Chi Square Test ◽  
Dug Wells ◽  
Dug Well ◽  
The Relationship

The well is one of the source water used for bathing, washing, and drinking by the citizens in Jiken Hamlet, Rarang Village, Terara Sub-District. Poor dug well construction conditions can affect the amount of coliform bacteria contained in the dug well water. The purpose of this study is to identify the construction of dug wells and the content of coliform bacteria in dug well water and determine the relationship between dug well construction and the content of coliform bacteria. This research is analytic with a cross sectional study design. The results were obtained from 11 samples of dug wells which were observed in construction and the coliform content was known that all samples did not requirements as good dug well construction. Coliform content test results showed that as many as 5 dug well water samples did not pass the clean water quality standards. The results of data analysis with the chi-square test variable construction of dug wells with coliform content variable  showed 0,172 > 0,05, then the concluded is the dug well not suitable to use by people in that area as a source of water for daily needs.

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