bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial orientations of angular momentum vectors of galaxies in Supercluster S [173+014+0082]
Authors: Malla Janak Ratna , Saurer Walter , Aryal B 
Published: January 2021

The spin vector orientation of 1302 SDSS (Sloan Digital Sky Survey) galaxies in Supercluster S[173+014+0082] having redshift 0.076 to 0.091 has been analysed. The positions, position angles and inclination angles of galaxies are used to convert two-dimensional observed parameters into three-dimensional angular momentum vectors of the galaxy using the `position angle-inclination' method. The expected isotropic distribution curves are determined performing numerical simulation by generating 107 virtual galaxies. The observed distribution is compared with the expected isotropic distribution curves using three statistical tools namely Chi-square test, auto-correlation test and Fourier test. Redshift map is studied and found that the distributions fit with the Gaussian. No preferred alignment of angular momentum vectors is noticed, supporting Hierarchy model of galaxy formation.
BIBECHANA 18 (2021) 26-32
Modulation frequency and velocity variation of ions in a magnetized plasma sheath for different obliqueness of the field
Authors: Adhikari Bhesha Raj , Lamichhane Hari Prasad , Khanal Raju 
Published: January 2021

The understanding of ion dynamics in magnetized plasma sheath is crucial for all applications of plasma. The velocity variation as well as modulation frequency of ions in a magnetized plasma sheath has been studied for different obliqueness of the magnetic field. The governing Lorentz force equation has been solved numerically for the given boundary conditions as applicable in the kinetic simulation of the sheath. For different obliqueness of the magnetic field, the average values, maximum amplitude, damping factor as well as frequency of oscillation are studied. The oscillating velocity components change at different rates depending on their orientation with respect to the field direction. Significant changes in the damping factor and modulation frequency has been observed for all components of velocity; however, the frequency of oscillation remains the same. As the obliqueness increases, shoulder natures in the components of velocity are observed.
BIBECHANA 18 (2021) 134-139
Prediction of daily global solar radiation using different empirical models on the basis of meteorological parameters at Trans Himalaya Region, Nepal
Authors: Joshi Usha , Karki I B , Chapagain N P , Poudyal K N 
Published: January 2021

Global Solar Radiation (GSR) is the cleanest and freely available energy resource on the earth. GSR was measured for six years (2010 -2015) at the horizontal surface using calibrated first-class CMP6 pyranometer at Kathmandu (Lat. 27.70o N, Long. 85.5oE and Alt. 1350m). This paper explains the daily, monthly, and seasonal variations of GSR and also compares with sunshine hour, ambient temperature, relative humidity, and precipitation to GSR. The annual average global solar radiation is about 4.16 kWh/m2/day which is a significant amount to promote solar active and passive energy technologies at the Trans-Himalaya region. In this study, the meteorological parameters are utilized in the regression technique for four different empirical models and finally, the empirical constants are found. Thus obtained coefficients are utilized to predict the GSR using meteorological parameters for the years to come. In addition, the predicted GSR is found to be closer to the measured value of GSR. The values are justified by using statistical tools such as coefficient of determination (R2), root mean square error (RMSE), mean percentage error (MPE), and mean bias error (MBE). Finally, the values of R2, RMSE, MPE, and MBE are found to be 0.792, 1.405, -1.014, and 0.011, respectively for the model (D), which are based on sunshine hour, temperature and relative humidity. In this model, the empirical constants, a = 0.155, b = 0.134, c = 0.014 and d = 0.0007 are determined which can be utilized at the similar geographical locations of Nepal.
BIBECHANA 18 (2021) 159-169
Effect of electron temperature in a magnetized plasma sheath using kinetic trajectory simulation
Authors: Chalise R , Pandit S K , Thakur G , Khanal R 
Published: January 2021

The understanding of the properties of magnetized plasma sheath has been various beneficial applications in surface treatment, electron emission gun, ion implantation, and nuclear fusion, etc. The effect of electron temperature on the magnetized plasma sheath has been studied for a fixed magnetic field and ion temperature. It has been observed that various plasma sheath parameters can be prominently altered by the varying temperature of the electron. The density of ion is influenced more by the change in electron temperature rather than the electron density. The temperature of the electron has a great effect at the wall, when electron temperature increases, the ion and electron densities at the wall decreases. This shows the potential at the wall also decreases follows the Poisson’s equation. Similarly, the electric field also decreases but total charge density increases when the electron temperature is increased.
BIBECHANA 18 (2021) 58-66
An overview on the non-destructive in-depth surface analysis of corrosion-resistant films: A case study of W-xCr deposits in 12 M HCl solution
Authors: Bhattarai Jagadish 
Published: January 2021

Non-destructive in-depth analysis of the surface films formed on the sputter-deposited binary W-xCr (x = 25, 57, 91 at %) alloys in 12 M HCl solution open to air at 30 °C was investigated using an angle-resolved X-ray photoelectron spectroscopic (AR-XPS) technique to understand the synergistic corrosion resistance effects of showing very low corrosion rates, even lower than both alloying metals of the deposits. The average corrosion rates of these three tungsten-based sputter deposits found to be more than five orders of magnitude (between 3.1 × 10−3 and 7.2 × 10−3 mm/y) to that of chromium and also nearly one order of magnitude lower than that of tungsten metals. Such high corrosion resistance of the sputter-deposited W-xCr alloys is due to the formation of homogeneous passive double oxyhydroxide film consisting of Wox and Cr4+ cations without any concentration gradient in-depth after immersion in 12 M HCl solution open to air at 30 °C from the study of the non-destructive depth profiling technique of AR-XPS. Consequently, both alloying elements of tungsten and niobium are acted synergistically in enhancing high corrosion resistance properties of the alloys in such aggressive electrolyte.
BIBECHANA 18 (2021) 201-213
Facile methods of preparing pure hydroxyapatite nanoparticles in ordinary laboratories
Authors: Pandey Gokarna , Dhakal Kedar Nath , Singh Ajaya Kumar , Dhungel Suresh Kumar , Adhikari Rameshwar 
Published: January 2021

The present work features some simple methods of preparing pure hydroxyapatite nanoparticles (nano-HAp), a useful biomaterial, via various wet chemical methods and using biogenic sources such as eggshells and animal bone. The nano-HAp hence prepared was subsequently characterized by FTIR spectroscopy and XRD technique. The FTIR spectra confirmed the presence of PO43- and OH- ions as major functional groups in the prepared material, with some additional peaks implying the presence of CO3- ions and adsorbed water molecules. The XRD patterns, in agreement with the JCPDS 09-432 data, demonstrated the crystalline nature of the nano-HAp and confirmed the phase as being apatite. The average grain diameter of the nanocrystallites was found in the range of 15-30 nm. The preparatory methods depicted herein can be easily employed in ordinary high school laboratories having basic facilities such as availability of distilled water, some handy glasswares, common laboratory chemicals and instruments such as balance, hot air oven and furnace.
BIBECHANA 18 (2021) 83-90
Schiff base metal complex as a potential therapeutic drug in medical science: A critical review
Authors: Chaudhary Narendra Kumar , Guragain Biswash , Chaudhary Siyanand Kumar , Mishra Parashuram 
Published: January 2021

The discovery of new chemotherapeutics with novel bioactivities and functionalities to fight current emerging diseases has become the most significant research in pharmaceutical science. Schiff bases are versatile pharmacophores that can form complexes by chelation with metals of different oxidation states. Over a few decades of intensive research on metal-based drugs, Schiff base metal complexes have been considered as the active field of research in coordination chemistry, owing to their valuable applications in various fields of science. As therapeutic drugs, they have potential applications as antibiotic, antimicrobial, antitumor, antiviral, anti-inflammatory, analgesic, antifungal, and many more. There has been a global threat of drug resistance in medical science in recent years because most of the pathogenic organisms are developing the ability to deactivate drug substances. For this reason, it requires urgent attention from chemical and pharmaceutical scientists to address the severe challenges of multidrug resistance. This review summarizes the current developments in the last few decades' research on the chemotherapeutic activities of Schiff base metal complexes.
BIBECHANA 18 (2021) 214-230
Study of aerosol optical properties at different tourist places of Nepal
Authors: Jha Rejeena , Adhikari Binod , Singh Dharmendra 
Published: January 2021

The comparative study of aerosol optical properties at different tourist places of Nepal has been performed. Langtang BC, Lumbini, Pokhara, Kathmandu-bode, EVK2-CNR, Jomsom and Kyanjin_Gompa were the places chosen for observation. We have analyzed the monthly and seasonal variation of aerosol optical properties for a different year of the above-mentioned places. AOD was found to be maximum in spring due to vegetation fire and land clearing for crop cultivation and, then in winter due to biomass burning, heating needs, pollution from bricks kilns, factories, and vehicles that contribute to winter haze. It consequently decreases in summer and was found to be minimum in autumn as summer constituent both dry and wet days and autumn starts with the ending of monsoon. But it was quite different in the case of Pokhara where it was minimum in summer than in autumn as Pokhara is the only city where maximum rainfall occurs in summer. We have also studied the relation between AOD and the corresponding wavelength. It was acclaimed that the AOD of shorter wavelength is more than the longer one which is because of the angstrom exponent. The relation between AOD and precipitated water has been observed and noticed one to one correspondence except July and August. The cross-correlation between these two factors found to be very high indicating a time lag of approximately 2 months with the presence of aerosol on cloud condensation nuclei (CCN).
BIBECHANA 18 (2021) 170-183
Предизвиците на преводот на Киберијадата од Станислав Лем
Authors: Tanuševska Lidija 
Published: December 2020

This article is about the specific language that the translator is faced with translating The Cyberiad by Stanisław Lem and some of the difficulties that are caused by the conception of the whole book. Considering that it is a science-fiction, it is natural that the main problems are neologisms made by Lem, but it appears that it is not the only one. We are trying to make an outline of the whole process of translating The Cyberiad, underlining some of the difficulties that the translator in Macedonian language could have come upon. Analyses contains of problems with word formation, poetic language, phraseology, archaisms and neologisms.
Single Point PICA Probing with an Avalanche Photo-Diode
Authors: Bruce Mike , Goruganthu Rama R. , McBride Shawn , Bethke David , Chin J.M. 
Published: December 2020

Abstract
For time resolved hot carrier emission from the backside, an alternate approach is demonstrated termed single point PICA. The single point approach records time resolved emission from an individual transistor using time-correlated-single-photon counting and an avalanche photo-diode. The avalanche photo-diode has a much higher quantum efficiency than micro-channel plate photo-multiplier tube based imaging cameras typically used in earlier approaches. The basic system is described and demonstrated from the backside on a ring oscillator circuit.
A Methodology to Reduce Ion Beam Induced Damage in TEM Specimens Prepared by FIB
Authors: Liu Chin Kai , Jen. Chen Chi , Yan.Chiou Jeh , Su David 
Published: December 2020

Abstract
Focused ion beam (FIB) has become a useful tool in the Integrated Circuit (IC) industry. It is playing an important role in Failure Analysis (FA), circuit repair and Transmission Electron Microscopy (TEM) specimen preparation. In particular, preparation of TEM samples using FIB has become popular within the last ten years [1]; the progress in this field is well documented. Given the usefulness of FIB, “Artifact” however is a very sensitive issue in TEM inspections. The ability to identify those artifacts in TEM analysis is an important as to understanding the significance of pictures In this paper, we will describe how to measure the damages introduced by FIB sample preparation and introduce a better way to prevent such kind of artifacts.
Leakage Isolation of Mixed-Signal Devices at Operating Modes
Authors: Xia William 
Published: December 2020

Abstract
Marginal internal leakage in mixed-signal devices at operating mode was isolated using a system evaluation board (SEB) and a highly sensitive infrared detector. Focused ion beam cross-section revealed a thin Ti/TiN metal residue (stringer) over two narrowly spaced metal lines. This is a quick and effective technique in isolating small leaky nets for integrated devices.
High Power Testing of Optical Connectors
Authors: Furcas Paola , Pastorelli Rosanna , Salmini Giulia , Vanzi Massimo 
Published: December 2020

Abstract
High optical power is considered as the source of failures in passive optical elements. Optical connectors, in particular, have been studied because of the unavoidable exposure of their optical interfaces to environmental issues during insertion and extraction. Cleaning and insertion/extraction procedures are investigated. Evidence for burn-out, depending on the different procedures, calls for new suitable rules for handling during equipment operation and testing.
Site Specific 2-D Implant Profiling Using FIB Assisted SCM
Authors: Jarausch Konrad , Richards John F. , Denney Lloyd , Guichard Alex , Russell Phillip E. 
Published: December 2020

Abstract
Advances in semiconductor technology are driving the need for new metrology and failure analysis techniques. Failures due to missing, or misregistered implants are particularly difficult to resolve. Two-dimensional implant profiling techniques such as scanning capacitance microscopy (SCM) rely on polish preparation, which makes reliably targeting sub 0.25 um structures nearly impossible.[1] Focused ion beam (FIB) machining is routinely used to prepare site-specific cross-sections for electron microscopy inspection; however, FIB induced artifacts such as surface amorphization and Ga ion implantation render the surface incompatible with SCM (and selective etching techniques). This work describes a novel combination of FIB machining and polish preparation that allows for site-specific implant profiling using SCM.
Enhancements of Non-contact Measurements of Electrical Waveforms on the Proximity of a Signal Surface Using Groups of Pulses
Authors: Du Fenglei , Bridges Greg , Thomson D.J. , Goruganthu Rama R. , McBride Shawn , Santana Mike 
Published: December 2020

Abstract
With the ever-increasing density and performance of integrated circuits, non-invasive, accurate, and high spatial and temporal resolution electric signal measurement instruments hold the key to performing successful diagnostics and failure analysis. Sampled electrostatic force microscopy (EFM) has the potential for such applications. It provides a noninvasive approach to measuring high frequency internal integrated circuit signals. Previous EFMs operate using a repetitive single-pulse sampling approach and are inherently subject to the signal-to-noise ratio (SNR) problems when test pattern duty cycle times become large. In this paper we present an innovative technique that uses groups of pulses to improve the SNR of sampled EFM systems. The approach can easily provide more than an order of magnitude improvement to the SNR. The details of the approach are presented.
Making Failure Analysis a Value Add Proposition in Today’s High Speed Low Cost PC environment
Authors: Lane Michael , Bjork Roger , Birdsley Jeff 
Published: December 2020

Abstract
This paper describes the Failure Analysis (FA) challenges that exist in today’s Personal Computer (PC) environment. The development and advancement in analytical tools and techniques have advanced the understanding and identification of failures, however economic and cost pressures have brought about a significant shift in the evaluation of Failure Analysis as a value add proposition as measured by the bottom line. This paper examines the factors and conditions that must be considered when assessing the FA scope and role, and its establishment as a critical value add requirement to maintain quality leadership and product performance expectations. The need for “Timely Actionable Information” becomes essential as part of the FA approach and a necessity to remain effective and competitive. This paper defines an approach by which this can be accomplished in the dynamic and high speed PC environment where product life cycles are consistently shrinking and the need for analytical techniques that yield “high confidence” answers quickly are becoming necessary. The changing conditions of the PC environment are driving the PC Failure Analysis groups to respond and adapt by establishing an Integrated Failure Analysis framework. This framework may span multiple organizations or companies and must deliver proactive information in a timely manner throughout the product life cycle (PLC). The information is proactive in the sense that FA is now identifying issues and prioritizing which of those to analyze, versus the historical model of waiting for a request by another organization.
Characterization of Reactive Ion Etching of Silicon Substrate for Backside Failure Mode Analysis
Authors: Wu Huixian , Cargo James 
Published: December 2020

Abstract
With technology scaling down to sub 0.16um and metalization exceeding 7 levels, the development of reproducible backside silicon sample preparation techniques becomes increasingly important to accurately localize defects. Bulk silicon thinning is a critical step in the backside sample preparation process. This paper will discuss two different ways for silicon thinning: reactive ion etching (RIE) alone, and RIE in conjunction with mechanical milling. In addition, the characterization and optimization of the RIE process for backside silicon thinning will be discussed in this paper. We have found mechanical milling works well for many package types; however, we have had difficulty reproducibly thinning certain package types such as very small die or packages where the wire bonds are in the plane of the silicon die and are in very close proximity to the edge of the die. In these cases, we have found that reactive ion etching (RIE) can be used successfully. We have also found that for package types where mechanical milling works, the combination of mechanical milling and reactive ion etching process is a useful technique for accurately controlling the final thickness of the silicon. This technique combines the speed of mechanically milling and the advantage of RIE process to accurately control the etch rate and etch process in the final stages of thinning the silicon die.
The Influence of Optical Beams on Semiconductor Devices During Failure Analysis
Authors: Zhang Charles , Thayer Matt , Herlinger Lowell , Dabney Greg , Gonzalez Manuel 
Published: December 2020

Abstract
A number of backside analysis techniques rely on the successful use of optical beams in performing backside fault isolation. In this paper, the authors have investigated the influence of the 1340 nm and 1064 nm laser wavelength on advanced CMOS transistor performance.
Wet Delineation of SEM Samples Having Cu Interconnects
Authors: Lai J.B. , Wang Y.P. , Kung J.Y. , Fu Y.C. , Hwang R.L. , Su David 
Published: December 2020

Abstract
For both FSG or C-doped oxide samples containing copper (Cu) metallization, Cu was often dissolved during wet delineation steps for cross-sectional SEM samples. Length effect was the important factor for avoiding Cu dissolution during wet delineation process. This paper presents practical methods to prevent Cu damage for FIB cross-sectional and mechanical polished SEM samples.
Obtaining Low Contact Resistance for Physical Sub-Micron Fault Isolation
Authors: Waggoner C. A. , Smith D. 
Published: December 2020

Abstract
The continued application and extension of Moore’s is Law driving semiconductor development into the deep submicron range. 90nm processes are pushing the limits of current technology, and announcements for 65nm and even smaller process developments are common place. Inspection and deprocessing tools are pacing these developments with moderate levels of success [1]. Fault isolation, however, and particularly physical fault isolation at these levels represents perhaps the most daunting of challenges facing today’s semiconductor companies. Possibly the most important failure analysis step, physical fault isolation of sub-micron devices, is growing increasingly more challenging. Traditional probe stations find limitation below 500nm feature sizes. Recent approaches to probing smaller geometries, such as AFM (Atomic Force Microscopy), have come up short in flexibility and applicability. Deposition of FIB pads can change circuit characteristics, is costly and time consuming, and is becoming increasingly more difficult as proximities decrease. Successful probing of structures smaller than 300nm require careful consideration to reduce and stabilize contact resistance (RC). A NANO-100TM probe station with SEM optics was used to analyze characteristics of, and the process needed to obtain stable, low RC for physical submicron fault isolation. Main discussion topics include probe tip oxidation, test timing and sample preparation. Probe tip selection, probe scrub, and attack angle are also mentioned. Recommendations and findings are presented for immediate application. It is shown that if the proper steps and considerations are made, stable RC of less than 10V is possible when probing sub-micron devices.
MIM Capacitor Reliability Fault Identification Using IR Microthermography and Automated De-processing: A Case Study
Authors: Steele J. , Remmel T. , Wilson S. , Nair M. , Sanders P. , Kiefer S. , Sutton M. , Paulson W. , Bigelow S. , Qualls D. , Gajewski D. , Martin M. , Walls J. 
Published: December 2020

Abstract
Advanced RF IC’s incorporate numerous components along with the CMOS circuitry. One component is a metal-insulator-metal (MIM) capacitor. Test capacitors have been stressed using accelerated voltage and temperature conditions to assess the long-term reliability. This paper describes a methodology for evaluating the MIM capacitors that have failed during reliability testing. IR microthermography was developed to detect leakage locations in areas that are not visible to optical inspection or standard emission microscopes. These areas were deprocessed to correlate the IR emission and physical defect locations. This information is utilized to understand the failures and improve the reliability.