Technical and Economical Comparison of Micro Powder Injection Molding

Atre Sundar V.,Wu Carl L.,Hwang Chul-Jin,Zauner Rudolf,Park Seong-Jin,German Randall M. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

In recent years, micro powder injection molding is being explored as an economical fabrication method for microcomponents in microsystems technology (MST). Technical and economic comparison was performed for processes. Molding experiment and simulation during the filling process were performed to evaluate several different geometries and processing conditions. The influence of material parameters and process conditions on mold filling were examined as a function of features size using microchannels as an example. It was found that the heat conductivity and viscosity of feedstock, geometry and mold temperature were the most critical parameters for complete filling of micro features.

The search for heavy Majorana neutrinos

Atre, Anupama,Han, Tao,Pascoli, Silvia,Zhang, Bin IOP Publishing Ltd 2009 Journal of high energy physics Vol.2009 No.5

The Majorana nature of neutrinos can be experimentally verified only via <I>lepton-number</I> violating processes involving charged leptons. We study 36 lepton-number violating (LV) processes from the decays of tau leptons and pseudoscalar mesons. These decays are absent in the Standard Model but, in presence of Majorana neutrinos in the mass range ∼ 100 MeV to 5 GeV, the rates for these processes would be enhanced due to their resonant contribution. We calculate the transition rates and branching fractions and compare them to the current bounds from direct experimental searches for Δ<I>L</I> = 2 tau and rare meson decays. The experimental non-observation of such LV processes places stringent bounds on the Majorana neutrino mass and mixing and we summarize the existing limits. We also extend the search to hadron collider experiments. We find that, at the Tevatron with 8 fb<SUP>−1</SUP> integrated luminosity, there could be 2σ (5σ) sensitivity for resonant production of a Majorana neutrino in the μ<SUP>±</SUP>μ<SUP>±</SUP> modes in the mass range of ∼10–180 GeV (10–120 GeV). This reach can be extended to ∼10–375 GeV (10–250 GeV) at the LHC of 14 TeV with 100 fb<SUP>−1</SUP>. The production cross section at the LHC of 10 TeV is also presented for comparison. We study the μ<SUP>±</SUP><I>e</I><SUP>±</SUP> modes as well and find that the signal could be large enough even taking into account the current bound from neutrinoless double-beta decay. The signal from the gauge boson fusion channel <I>W</I><SUP>+</SUP><I>W</I><SUP>+</SUP>→ℓ<SUP>+</SUP><SUB>1</SUB>ℓ<SUP>+</SUP><SUB>2</SUB> at the LHC is found to be very weak given the rather small mixing parameters. We comment on the search strategy when a τ lepton is involved in the final state.

The Information Center and Productivity tools Working in Harmony

Atre, Shaku 연세대학교 경영대학원 1988 經營論叢 Vol.21 No.2

이와 같은 producticity tools를 구입하는데 있어서 하나 주의할 점은 소프트웨어가 시끌법석한 말들만 가지고 광고되고 있다는 점에 있다. 몇몇 광고 문앙은 intergrated, user-frie-dndly, relationalm data base mgt. system, menu-driver 그리고 물론 PC-Compatoble 등과 같은 말로 가득차 있다. PC기술의 발전은 응용기기 프로그래머가 없어도 우리가 이를 사용할 수 있게끔 할 뿐만 아니라, 또다른 영향을 미치고 있다. 우리는 모두 응용기기 프로그래머가 되어가고 있는데, 이는 마치 우리 모두가 전화 교환수가 되어버리는 것과 같다. 기업발전을 위한 정보에 기초를 둔 제품들은 최종사용자들이 쉽게 조작가능한 S/W의 수요와 프로그래머를 위한 응용기기 개발에의 갈등을 동시에 만족시켜줄 수 있는 응용개발 환경을 선택해야 한다. DP 전문가들은 본체 대신에 마이크로 컴퓨터를 이용하여 최종사용자들과 함께 점차적으로 응용기기 프로그래밍을 실시할 것이다. Information Center는 우리가 지금 전기와 물의 효용을 당연히 받아들이는 것과 마찬가지로 역시 당연히 유용한 시설로서 받아들여지게 될 것이다.

District-wise estimation of Basic reproduction number (R0) for COVID-19 in India in the initial phase

Shil Pratip,Atre Nitin M.,Patil Avinash A.,Tandale Babasaheb V.,Abraham Priya 대한공간정보학회 2022 Spatial Information Research Vol.30 No.1

SARS-CoV-2 or COVID-19 was introduced into India by multiple sources generating local clusters and leading to the nationwide spread. A retrospective study has been conducted on the epidemiological features and spatial spread of COVID-19 in India during February 2020–March 2021. For each district, the cumulative number of confirmed COVID-19 cases were fitted to exponential growth model for the initial phase of the outbreak (the first 7–15 days). From the estimated growth rate, epidemiological parameters like the Basic reproduction number (R0) and epidemic doubling time (s) were determined. Using Q-GIS software, we have generated the all India distribution maps for R0 and s. COVID-19 spread rapidly covering majority of the districts of India between March and June 2020. As on 1st March 2021, a total of 715 out of 717 districts have been affected. The R0 range is at par with the global average. A few districts, where outbreaks were caused by migrant workers coming home, intense transmission was recorded R0[7. We also found that the spread of COVID-19 was not uniform across the different districts of India. The methodology developed in the study can be used by researchers and public health professionals to analyze and study epidemics in future.

수요처 에너지관리시스템 구성요소 도출

엔이씨파워,고등기술원,ATR 한국열환경공학회 2021 한국열환경공학회 학술대회지 Vol.2021 No.추계

District-wise estimation of Basic reproduction number (R0) for COVID-19 in India in the initial phase

Shil Pratip,Atre Nitin M.,Patil Avinash A.,Tandale Babasaheb V.,Abraham Priya 대한공간정보학회 2022 Spatial Information Research Vol.30 No.2

SARS-CoV-2 or COVID-19 was introduced into India by multiple sources generating local clusters and leading to the nationwide spread. A retrospective study has been conducted on the epidemiological features and spatial spread of COVID-19 in India during February 2020–March 2021. For each district, the cumulative number of confirmed COVID-19 cases were fitted to exponential growth model for the initial phase of the outbreak (the first 7–15 days). From the estimated growth rate, epidemiological parameters like the Basic reproduction number (R0) and epidemic doubling time (s) were determined. Using Q-GIS software, we have generated the all India distribution maps for R0 and s. COVID-19 spread rapidly covering majority of the districts of India between March and June 2020. As on 1st March 2021, a total of 715 out of 717 districts have been affected. The R0 range is at par with the global average. A few districts, where outbreaks were caused by migrant workers coming home, intense transmission was recorded R0[7. We also found that the spread of COVID-19 was not uniform across the different districts of India. The methodology developed in the study can be used by researchers and public health professionals to analyze and study epidemics in future.

Effects of process parameters in plastic, metal, and ceramic injection molding processes

이시우,안석영,황철진,박성진,Sundar V. Atre,김주권,Randall M. German 한국유변학회 2011 Korea-Australia rheology journal Vol.23 No.3

Plastic injection molding has been widely used in the past and is a dominant forming approach today. As the customer demands require materials with better engineering properties that were not feasible with polymers, powder injection molding with metal and ceramic powders has received considerable attention in recent decades. To better understand the differences in the plastic injection molding, metal injection molding, and ceramic injection molding, the effects of the core process parameters on the process performances has been studied using the state-of-the-art computer-aided engineering (CAE) design tool, PIMSolver The design of experiments has been conducted using the Taguchi method to obtain the relative contributions of various process parameters onto the successful operations.

PROXIMAL TYPE CONVERGENCE RESULTS USING IMPLICIT RELATION AND APPLICATIONS

O. P. Chauhan,B. Chaudhary,H. Atre 경남대학교 기초과학연구소 2024 Nonlinear Functional Analysis and Applications Vol.29 No.1

The goal of this study is to instigate various new and novel optimum proximity point theorems using the notion of implicit relation type $\beth$-proximal contraction for non-self mappings. An illustrated example is used to demonstrate the validity of the obtained results. Furthermore, some uniqueness results for proximal contractions are also furnished with partial order and graph. Various well-known discoveries in the present state-of-the-art are enhanced, extended, unified, and generalized by our findings. As an application, we generate some fixed point results fulfilling a modified contraction and a graph contraction, using the profundity of the established results.

Predicting Powder-Polymer Mixture Properties for PIM Design

Kate, K.H.,Enneti, R.K.,Park, S.-J.,German, R.M.,Atre, S.V. CRC PRESS LLC 2014 CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIE Vol.39 No.3

Powder injection molding (PIM) is a high-volume manufacturing technique for fabricating ceramic and metal components that have complex shapes. In PIM design, it is important to know the injection molding behavior at different powder-polymer compositions so as to understand the trade-offs between ease-of-fabrication, process throughput, and part quality at the design stage. A limited database of materials properties at different powder-polymer compositions is a significant challenge that needs to be addressed in order to conduct accurate computer simulations that aid part and mold design in PIM. However, accurate material property measurements are expensive and time-consuming. In order to resolve these conflicting challenges it is hypothesized that experimental measurements of material properties of a filled polymer at a specific filler content combined with similar measurements of unfilled polymer will be adequate to estimate the dependence of properties on filler content using rule-of-mixture models. To this end, this article focuses on a literature review of experimental data obtained from measurements of rheological, thermal, and mechanical properties for a wide range of powder-polymer mixtures at various filler volume fractions. The experimental data were compared to property estimates using various predictive models. It is expected that the current review will be valuable in selecting appropriate predictive models for estimating properties based on the input data requirements for commercially available mold-filling simulation platforms such as Moldflow (R) and PIMSolver (R). The combined protocol will be useful to design new materials and component geometries as well as optimize process parameters while eliminating expensive and time-consuming trial-and-error practices prevalent in PIM.

Effects of process parameters in plastic, metal, and ceramic injection molding processes

Lee, Shi-W.,Ahn, Seok-Young,Whang, Chul-Jin,Park, Seong-Jin,Atre, Sundar V.,Kim, Jook-Won,German, Randall M. 한국유변학회 2011 Korea-Australia rheology journal Vol.23 No.3

Plastic injection molding has been widely used in the past and is a dominant forming approach today. As the customer demands require materials with better engineering properties that were not feasible with polymers, powder injection molding with metal and ceramic powders has received considerable attention in recent decades. To better understand the differences in the plastic injection molding, metal injection molding, and ceramic injection molding, the effects of the core process parameters on the process performances has been studied using the state-of-the-art computer-aided engineering (CAE) design tool, PIMSolver$^{(R)}$ The design of experiments has been conducted using the Taguchi method to obtain the relative contributions of various process parameters onto the successful operations.