Advanced Aspects of Engineering Research Vol. 16

In the spectral region of the excitons, reverse sign spectra of the Verdet constant V(\(\hbar\omega\)) are observed in the optical active crystals Bi₁₂ SiO₂₀ and in the doped optical active crystals Bi₁₂ SiO₂₀:M (M=Co,Fe).. The spectral area, in which the sign of the doped crystals are changed, is moved in comparison to that of undoped crystals, and the energy of the photons \(\hbar\omega\), at which an inversion of the si_X of the V(\(\hbar\omega\)) of doped crystals is observed, is less than the one of the undoped crystals. The reverse si_X spectra ofthe doped crystals Bi₁₂ SiO₂₀ in the spectral region of the excitons is clarified By an exchange interaction between the localized paramagnetic ions Co^(2+) (or Fe) and the charge carriers forming the excitons. The main internal defect (Bi_Si^(3+) +h^+) in Bi₁₂ SiO₂₀ in Bi₁₂ SiO₂₀ describes this effect in undoped crystals. The changing of the si_x of V(\(\hbar\omega\)) in this defect by one exchange interaction ofthe ligand ion O^- with a connected exciton (e^-+h^+) in this defect according to a simplified model.

The symmetry C6v of hexagonal CdS and CdSe crystals exhibits "weak" gyrotropy. In crystals of CdS and CdSe deformed by a torsional moment guided along the optical axis, a significant gyrotropic effect is observed. The Polarizer-Crystal-Analyzer (P-C-A) device is used. Light does not pass through the device (P–C–A) with crossed P and A and an undeformed CdS or CdSe crystal. The crystal's symmetry is reduced to C6, and it gains gyrotropic properties as a result of the torsion. With a deformed CdS or CdSe crystal, the device (P-C-A) starts to miss light. The intensity of the light that passed through the structure (P–C-A) with deformed CdS or CdSe crystal is 85-90% of the incident light intensity for broad values of the torsional moments, according to our research.

Multicomponent melt solidification has been studied using a non-equilibrium model, in which a Stefan problem with two boundaries is solved numerically, the boundaries being between the solid phase and the two-phase transition zone and between the two-phase transition zone and the liquid phase. A porous medium with variable porosity is used to depict the two-phase zone. By analogy with Darcy's law, consideration is given to the additional force resisting melt flow due to porosity. The experiment on Sn-20 wt. % Pb binary alloy solidification by the process of downward-directed crystallization along the gravity vector was computer simulated.  Shown in the paper are the results of a quasi two-dimensional benchmark experiment on horizontal (i.e., at the right angle to the gravity vector) directional solidification of a binary Sn-3 wt.%Pb alloy. The calculations were carried out using two crystallisation models: equilibrium and non-equilibrium crystallisation.The non-equilibrium model is shown to provide a more accurate representation of the thermal field evolution and solute distribution induced by natural convection.

Variable frequency and variable voltage are increasingly supplied by a three-level voltage source inverter for variable speed applications. The appropriate output voltage at the line side of the inverter is obtained using a suitable pulse width modulation technique. This chapter investigates the three-level Diode Clamped or Neutral Point Clamped topology, which is a popular multi-level topology. The modulation wave is generated using two Sine-triangle methods and two Space Vector Pulse Width Modulation methods. To produce the PWM signals for the three phases, these modulation waves are compared to a triangular carrier. Instead of the three phase modulating waves used in SPWM, a rotating reference voltage vector is used as a voltage reference in SVPWM methods. The magnitude and frequency of the line side's fundamental variable are controlled by the magnitude and frequency of the reference vector, respectively. Because of its higher dc bus utilization and lower harmonic distortion than SPWM, Space Vector Modulation has become a common PWM technique for three-phase Voltage Source Inverters. In MATLAB/SIMULINK software, the four PWM methods are simulated and compared for THD and Capacitor Balance. Embedded Editor and Matlab Editor Functions are used to build the programs. As compared to Sine PWM, simulation results show that Space vector PWM better utilizes dc bus voltage, produces less THD, and improves capacitor balance.

Rice is one of the most important foods for humans on earth. India and China are two of the world's most rice-dependent countries. The yield of this crop is determined by a number of factors, including soil, water supply, pesticides used, time period, and disease infection. Rice Plant Disease (RPD) is one of the most significant factors affecting rice quantity and quality.  Farmers face a constant challenge in determining the form of rice plant disease and taking timely corrective action against it. Although the rice plant is susceptible to a variety of diseases, the most common are Bacterial Leaf Blight (BLB), Brown Spot (BS), and Leaf Smut (LS).Since the infected leaf must be processed by the human eye, identifying this disease is extremely difficult. To define and classify the RPD, we used machine learning techniques in this chapter. We used the UCI Machine Learning repository to gather data on contaminated rice plants. The data collection contains 120 images of contaminated rice plants, with 40 BLB images, 40 BS images, and 40 LS images. RandomForest, REPTree, and J48 are decision tree-based machine learning algorithms used in the experiments.  We used ColorLayoutFilter, which is provided by WEKA, to extract numerical features from the infected images. The experimental analysis makes use of 65% of the data for training and 35% of the data for testing. The Random Forest algorithm performs exceptionally well in predicting RPD, according to the experiments.

This chapter focuses on advanced experiments and improvements in the security features of the SATA solid-state drives. In modern computer applications, the quantity of data is growing day by day, and accordingly, the size of storage media is also increasing rapidly. Flash memories are used in most storage devices, one of which is a Solid State drive. Solid-state drives, or SSDs, are non-volatile data storage devices that store data in NAND or NOR flash memories, providing features similar to traditional hard disk drives (HDD). This chapter provides a comparative study of Solid-state drives over Hard-disk drives. Further, a technique is designed and implemented to enhance SATA Solid-state drives security features in terms of user authentication, access control, and media recovery from the ATA security feature set.

Hackers are usually prepared to hack  confidential documents for their vested interests.  The most difficult task is to establish a secure link between the secret message and image quality. The proposed scheme combines cryptography and image steganography techniques to avoid illegal attacks by an unknown person. This scheme will enable image security and message security. The International Data Encryption Algorithm (IDEA) cryptographic algorithms and Discrete Cosine Transform (DCT) based steganography algorithms based functional approach.   The purpose of cryptography is to encrypt and decrypt the document. Steganography is the technique of hiding documents within an image with increasing payload for the secure transmission of confidential data over the internet. In this paper, we present a single application to hide the information by the sender, which is an essential document and secret file.  The form will be invisible to an unauthorized person. PSNR of 90.06 dB with a payload of 52,400 bytes of information in an image.

The aim of this chapter is to discuss the development of a crimping machine capable of crimping hydraulic hoses without the use of electricity. A thorough analysis of the literature suggests that it was the fabrication of electrically powered crimping machines that motivated the authors to create a hydraulically powered crimping machine. This type of crimping machine is extremely useful when the rig is in motion and is also ideal for emergency crimping to prevent shutdown time. The author designed critical components of the system using Autodesk inventor software and obtained a safety factor greater than one for all critical components. A safety factor of less than one results in hazardous operating conditions for vital components. The entire assembly has been successfully fabricated for the necessary crimping on a 19.05 mm hose. The crimping machine was successfully checked for crimping the specified hose size. The machine's configuration can be modified to fit a variety of die sizes for crimping hoses of various sizes.

Polyphase Sequences with good autocorrelation properties, such as Pn {n=1,2,3,4,x}, Frank, Golomb, and the Chu, find many applications in RADAR, SONAR, and communication. Merit Factor (MF), ISL (Integrated Sidelobe Level) are performance measures used to evaluate the goodness of any sequence. This work uses a cyclic algorithm approach to generate Polyphase sequences with lengths ranging from 10^2 to 10^3 . The merit factor and correlation features of these cyclic algorithm techniques outperform the standard scenario. The average merit factor for lengths of 100 and 1000 was found to be 40.39 and 92.02, respectively. The correlation graphs of polyphase sequences using the cyclic technique are compared to the normal case.P2 sequences with a higher merit factor for odd integer square length were made achievable using this method. The merit factor values and correlation plots of four successive even and odd integer squared length sequences were compared.For these Polyphase sequences, a cyclic algorithmic approach for collecting design metrics has been implemented in MATLAB.

Twitter is one of the most popular social media networks and therefore it is prone to misuse. One of the ways in which people misuse Twitter is by spamming. Spam becomes an issue once a communication medium especially one, which enables global communication and handle huge amount of online data. Since Twitter is popular among so many people, it makes it easy for spammers to thrive. Spammers are people who send unwanted messages to people to either advertise a product or lure the victims into clicking malicious links, which may affect their user systems. The main objective of these spammers is usually to make money from their victims. In the last years, several systems has-been made with the aim of determining whether a user is a spammer or not. However, these systems cannot filter each spam message and a different account can be created by a spammer and used to send other messages. This paper proposes a content-based approach, which can be used to filter spam tweets. The approach involves using tweets in machine learning and compression algorithms in order to filter the undesired tweets. The technology will continue to develop further helping to flush out spammers and improve Twitter space. Spam detection has become an integral part of Twitter in providing security to twitter users against cyber criminals and other malicious entities.

A cost effective and sensitive chemical sensor is developed for detection ofFe⁺² based on evanescent wave fiber optic absorption technique. A high quality LED source is used in sensing mechanism. Multimode sensor grade plastic clad silica (PCS) fiber is adopted as sensing arm, whose centre cladding region  is taken out to interact with the surrounding region(Fe⁺² ions).This unclad region of the PCS fiber is used as a sensing element in this experiment. The sensor developed is highly sensitive over the dynamic range of concentration from 0.1ppm to 100ppm for the detection of Fe⁺² in water.

In the Philippines, farming employs one-third of the workforce. Farmers played an essential part in delivering fresh food to every family on a regular basis for our wellbeing. Assisting farmers in building a stronger network to market their products resulted in the agricultural sector's long-term viability. The development of an agricultural forecasting mobile application will benefit both farmers and traders by ensuring that produced crops are profitable. Agricultural forecasting applications will use the developed architecture design. The study looked into the aspects that went into the development of a mobile application to help farmers.

The employment of various statistical methods aided in the provision of in-depth analysis, resulting in a more widely acceptable design for farmers.

The findings demonstrate that identifying some common concerns in offering online services will also help to resolve some challenges and provide answers to the best practises in agricultural production forecasting. 

It stated that having a mobile agricultural forecasting application solved the problems associated with farm waste production.

The application will assist farmers in determining the degree of crop demand in the market and navigating to the location where farm produce demand is high in the participating trading post. This helped farmers and the government enhance the agricultural sector, which was lagging behind other developing countries.

Raw clay has been used in housing construction from ancient times and is still used now. Traditional habitat, which consists of diverse buildings scattered around our earth, provides proof. Rain water wash, among any other pathologies impacting naked earthen walls, is a serious concern that requires careful consideration. This explains why this study on the protection mechanisms for these types of walls is so interesting. This article describes an experiment with low walls built of raw clay mixed with composite protective materials (both traditional and modern), which were subjected to intense flooding. The locust bean tree (local tree) fruit husk extract applied to raw clay mortar and correctly blended appears to provide superior ability to protect walls from water assault, according to the results of the tests examined through the efficiency of the protecting materials. In addition, consistency and plasticity tests showed improved performance in clay material qualities.

Research carried out shows that the decoction of pods of Parkia biglobosa (néré) is rich in tannins compounds including gallic acid, epicatechin gallate and epigallocatechin.

General management programmes have become outdated as management education has progressed. Specialised management programmes are the flavour of the day.  This demands professors having specialised knowledge in one or more of the primary fields. This entails a detailed understanding and assimilation of skills that must be transferred to students pursuing management education. The function of the faculty is critical in generating not only graduates but also citizens who are valued internationally.

Only when the workplace is packed with positive vibes and ambience can faculty be focused. The impact of several workplace factors on faculty performance is examined in this research. The influence was decoded using primary data collected from 629 faculty members and regression analysis. Faculty can enjoy development only when they are pushed to achieve greater heights. This necessitates good leadership and continuous mentoring along the way.

The purpose of this paper is to investigate the noise power of ASE (Amplified Spontaneous Emission) using the simulation model EDFA (Erbium Doped Fiber Amplifier) cascaded with EYCDFA (erbium-ytterbium co-doped fibre amplifier) in 4-16 channels of transmitters combined by optical multiplexer and sent the output to EDFA in series with EYCDFA in single backward pumping using the wavelength of 980nm. The performance of this simulation model was evaluated using the parameters Gain, forward output signal power, and ASE noise, and the results were summarized. The results of 2- 16 channels of RZ transmitter and 2- 16 channels of NRZ transmitter were integrated in the simulation model with optical multiplexer and multiplexed signal sent to cascaded Erbium amplifiers with pumping CW (continuous wave) Laser source with wavelength 980nm and Filter. EDFA Gain, output signal power, and ASE noise are correctly represented by the model. The simulation results demonstrate that utilising EDFA and EYCDFA to choose a cautious fibre length of 20m and a pump power of 1mw in single pumping yields ASE noise of 0.005mw and zero milli watts.

The oscillators, which are essential for precise timing, are at the heart of a satellite-based navigation system. The purpose of this research is to investigate the crucial role that space-borne oscillators play in increasing the performance of GNSS and satellite-based augmentation systems (SBAS). The African contribution to the SBAS, the NIGCOMSAT-1R navigation payload, which uses externalised 10 MHz Master Oscillators in a 3 X 4 hybrid array configuration, examines the efficacy of Location Based Services using Navigation for Emergency and Crisis Management, among other applications.

With the advent of low-cost 3D display devices, content protection for image-based 3D data is becoming increasingly important. The rendering is based on depth images (DIBR) One type of picture-based 3D data is the 3D picture, which is made up of the centre picture and the depth image supplied by the content provider. At the content consumer side, the left-eye picture and the right-eye picture are produced from the centre picture and the depth image. Blind watermarking for DIBR 3D images is a topic that is rarely researched in the literature. A unique blind multiple watermarking approach is suggested in this study to address the content protection problem of DIBR 3D pictures . We discovered that appropriate embedding order is significantly more crucial in watermarking DIBR 3D pictures than the standard requirement of mutual orthogonality among reference patterns for multiple water mark embedding. The suggested approach is resistant to JPEG compression and noise addition assaults, according to experimental results. More interestingly, the suggested watermarking is shown to be capable of tolerating broad range fluctuations in the depth picture during rendering.