Summary

HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Chemical Force Microscopy
In materials science, chemical force microscopy (CFM) is a variation of atomic force microscopy (AFM) which has become a versatile tool for characterization of materials surfaces. With AFM, structural morphology is probed using simple tapping or contact modes that utilize van der Waals interactions between tip and sample to maintain a constant probe deflection amplitude (constant force mode) or maintain height while measuring tip deflection (constant height mode). CFM, on the other hand, uses chemical interactions between functionalized probe tip and sample. Choice chemistry is typically gold-coated tip and surface with R–SH thiols attached, R being the functional groups of interest. CFM enables the ability to determine the chemical nature of surfaces, irrespective of their specific morphology, and facilitates studies of basic chemical bonding enthalpy and surface energy. Typically, CFM is limited by thermal vibrations within the cantilever holding the probe. This limits force measurement resolution to ~1 pN which is still very suitable considering weak COOH/CH3 interactions are ~20 pN per pair. Hydrophobicity is used as the primary example throughout this consideration of CFM, but certainly any type of bonding can be probed with this method.
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  • 23 Nov 2022
Topic Review
Cyber Security Awareness
Cyber security awareness refers to how much end-users know about the cyber security threats their networks face, the risks they introduce and mitigating security best practices to guide their behavior. End users are considered the weakest link and the primary vulnerability within a network. Since end-users are a major vulnerability, technical means to improve security are not enough. Organizations could also seek to reduce the risk of the human element (end users). This could be accomplished by providing security best practice guidance for end users' awareness of cyber security. Employees could be taught about common threats and how to avoid or mitigate them.
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  • 23 Nov 2022
Topic Review
Let's Encrypt
Let's Encrypt is a certificate authority that provides X.509 certificates for Transport Layer Security (TLS) encryption at no charge. The certificate is valid for 90 days, during which renewal can take place at anytime. The offer is accompanied by an automated process designed to overcome manual creation, validation, signing, installation, and renewal of certificates for secure websites. It launched on April 12, 2016. The project claims to make encrypted connections to World Wide Web servers ubiquitous. By eliminating payment, web server configuration, validation email management and certificate renewal tasks, it is meant to significantly lower the complexity of setting up and maintaining TLS encryption. On a Linux web server, execution of only two commands is sufficient to set up HTTPS encryption and acquire and install certificates. To that end, a software package was included into the official Debian and Ubuntu software repositories. Current initiatives of major browser developers such as Mozilla and Google to deprecate unencrypted HTTP are counting on the availability of Let's Encrypt. The project is acknowledged to have the potential to accomplish encrypted connections as the default case for the entire web. Only domain-validated certificates are being issued, since they can be fully automated. Organization Validation and Extended Validation Certificates are not available. By being as transparent as possible, they hope to both protect their own trustworthiness and guard against attacks and manipulation attempts. For that purpose they regularly publish transparency reports, publicly log all ACME transactions (e.g. by using Certificate Transparency), and use open standards and free software as much as possible. Support of ACME v2 and wildcard certificates was added in March 2018.
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  • 23 Nov 2022
Topic Review
Roots Reggae Library
The Roots Reggae Library is a website that lists reviews of discographies of Reggae artists. It contains detailed written descriptions of albums, songs and the style of the artist. There are currently 33 discographies on the website. The content of the website consists of information on a large range of albums within the Reggae genre, some of which are extremely rare and hard to get by elsewhere. A number of artists discographies are uniquely indexed and/or newly created. Songs with lyrics other than English are interpreted in English. This is done in collaboration with various people around the world.
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Topic Review
On Ancient Medicine
The treatise On Ancient Medicine (Greek: Περὶ Ἀρχαίας Ἰατρικῆς; Latin: De vetere medicina) is perhaps the most intriguing and compelling work of the Hippocratic Corpus. The Corpus itself is a collection of about sixty writings covering all areas of medical thought and practice. Traditionally associated with Hippocrates, (c. 460 BC – c. 370 BC) the father of Western medicine, philological evidence now suggests that it was written over a period of several centuries and stylistically seems to indicate that it was the product of many authors dating from about 450-400 B.C.
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Topic Review
Mahindra & Mahindra
Mahindra & Mahindra Limited is an India multinational vehicle Automotive industry corporation headquartered in Mumbai , Maharashtra, India. It was established in 1945 as Muhammad & Mahindra and later renamed as Mahindra and Mahindra. It is one of the largest vehicle manufacturers by production in India and the largest manufacturer of tractors in the world. It is a part of the Mahindra Group, an Indian conglomerate. It was ranked 17th on a list of top companies in India by Fortune India 500 in 2018. Its major competitors in the Indian market include Maruti Suzuki and Tata Motors.
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Topic Review
Hybrid Plant
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering times, pollen vectors, inhibition of pollen tube growth, somatoplastic sterility, cytoplasmic-genic male sterility and the structure of the chromosomes. A few animal species and many plant species, however, are the result of hybrid speciation, including important crop plants such as wheat, where the number of chromosomes has been doubled. Human impact on the environment has resulted in an increase in the interbreeding between regional species, and the proliferation of introduced species worldwide has also resulted in an increase in hybridisation. This genetic mixing may threaten many species with extinction, while genetic erosion from monoculture in crop plants may be damaging the gene pools of many species for future breeding. A form of often intentional human-mediated hybridisation is the crossing of wild and domesticated species. This is common in both traditional horticulture and modern agriculture; many commercially useful fruits, flowers, garden herbs, and trees have been produced by hybridisation. One such flower, Oenothera lamarckiana, was central to early genetics research into mutationism and polyploidy. It is also more occasionally done in the livestock and pet trades; some well-known wild × domestic hybrids are beefalo and wolfdogs. Human selective breeding of domesticated animals and plants has resulted in the development of distinct breeds (usually called cultivars in reference to plants); crossbreeds between them (without any wild stock) are sometimes also imprecisely referred to as "hybrids". Hybrid humans existed in prehistory. For example, Neanderthals and anatomically modern humans are thought to have interbred as recently as 40,000 years ago. Mythological hybrids appear in human culture in forms as diverse as the Minotaur, blends of animals, humans and mythical beasts such as centaurs and sphinxes, and the Nephilim of the Biblical apocrypha described as the wicked sons of fallen angels and attractive women.
  • 5.2K
  • 24 Nov 2022
Topic Review
Depersonalization Disorder
Depersonalization disorder (DPD), also known as depersonalization/derealization disorder (DPDR), is a mental disorder in which the person has persistent or recurrent feelings of depersonalization or derealization. Depersonalization is described as feeling disconnected or detached from one's self. Individuals experiencing depersonalization may report feeling as if they are an outside observer of their own thoughts or body, and often report feeling a loss of control over their thoughts or actions. In some cases, individuals may be unable to accept their reflection as their own, or they may have out-of-body experiences. Derealization is described as detachment from one's surroundings. Individuals experiencing derealization may report perceiving the world around them as foggy, dreamlike/surreal, or visually distorted. In addition to these depersonalization-derealization disorder symptoms, the inner turmoil created by the disorder can result in depression, self-harm, low self-esteem, phobias, panic attacks, and suicide. It can also cause a variety of physical symptoms, including chest pain, blurry vision, visual snow, nausea, and the sensation of pins and needles in one's arms or legs. Depersonalization-derealization disorder is thought to be caused largely by interpersonal trauma such as childhood abuse. Triggers may include significant stress, panic attacks, and drug use. Studies suggest a uniform syndrome for chronic depersonalization/derealization regardless of whether drugs or an anxiety disorder is the precipitant. It is unclear whether genetics plays a role; however, there are many neurochemical and hormonal changes in individuals with depersonalization disorder. The disorder is typically associated with cognitive disruptions in early perceptual and attentional processes. Diagnostic criteria for depersonalization-derealization disorder include persistent or recurrent feelings of detachment from one's mental or bodily processes or from one's surroundings. A diagnosis is made when the dissociation is persistent and interferes with the social or occupational functions of daily life. However, accurate descriptions of the symptoms are hard to provide due to the subjective nature of depersonalization and derealization and persons' ambiguous use of language when describing these episodes. In the DSM-5, it was combined with derealization disorder and renamed "depersonalization/derealization disorder" ("DDPD"). In the DSM-5, it remains classified as a dissociative disorder, while the ICD-10 calls it "depersonalization-derealization syndrome" and classifies it as a neurotic disorder. Although the disorder is an alteration in the subjective experience of reality, it is not a form of psychosis, as the person is able to distinguish between their own internal experiences and the objective reality of the outside world. During episodic and continuous depersonalization, the person can distinguish between reality and fantasy and the grasp on reality remains stable at all times. While depersonalization-derealization disorder was once considered rare, lifetime experiences with it occur in about 1–2% of the general population. The chronic form of the disorder has a reported prevalence of 0.8 to 1.9%. While brief episodes of depersonalization or derealization can be common in the general population, the disorder is only diagnosed when these symptoms cause substantial distress or impair social, occupational, or other important areas of functioning.
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  • 23 Nov 2022
Topic Review
Centralised Generation
Centralised generation refers the common process of electricity generation through large-scale centralised facilities, through Transmission lines to consumer. These facilities are usually located far away from consumers and distribute the electricity through high voltage transmission lines to a substation where it is then distributed to consumers. The basic concept being that incredibly large stations create electricity for a large group of people. The Vast majority of electricity used in Australia as well as the United States is created from Centralised Generation. Most Centralised Power Generation comes from large power plants run by fossil fuels such as coal or natural gas. Nuclear or large hydroelectricity plants are also commonly used. Many disagree with the processes of Centralised Generation as it often relies on electrical generation through processes of the combustion of fossil fuels, which are bad for the environment. However unsustainable the current system is, it is by far the most widely used, reliable and efficient system that is currently in use. Centralised Generation is fundamentally the opposite of distributed generation. Distributed generation is the small-scale generation of electricity to smaller groups of consumers. This can also include independently producing electricity by either solar or wind power. In recent years Distributed generation as has seen a spark in popularity due to its propensity to use renewable energy generation methods such as wind and solar.
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  • 23 Nov 2022
Topic Review
Supply-Chain Optimization
Supply-chain optimization is the application of processes and tools to ensure the optimal operation of a manufacturing and distribution supply chain. This includes the optimal placement of inventory within the supply chain, minimizing operating costs (including manufacturing costs, transportation costs, and distribution costs). This often involves the application of mathematical modelling techniques using computer software.
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