Scientific Research and Essays

Food safety has always been the focus of attention from all walks of life as it has been treated as one of the important indicators of the development of a country, concerning national health, industrial security and social stability. On the basis of empirical data, this study analyzed consumer trust in food safety from the perspective of consumers’ risk perception, consumer behavior and food safety regulation. It is found that consumers’ trust in food safety in China is not optimistic and governance of food safety remains to be improved.

This project aims to determine the effect of different coarse aggregate sizes and type on the compressive strength of concrete. The most important property of concrete is its compressive strength. The exceeding strength of concrete is as a result of the presence of coarse aggregate. Normal concrete is being produced from different types of aggregate and size and this imparts different property to the resulting concrete. The research has established that the coarse aggregates and their sizes play critical roles in the development of adequate strength in concrete. Fine aggregate is normal sand obtained from a borrow pit. Preliminary laboratory investigation was conducted to ascertain the suitability of using the aggregates for construction work. Tests conducted include sieve analysis, bulk density, and specific gravity. From the graph of the sieve analysis for fine and coarse aggregate, the coefficient of uniformity calculated was 1.5 and 3.45 respectively. It was observed that with proper mixing, the slump test results did not witness shear or collapse type of slump rather there were true slump in all cases of the test. The result of the slump test for 12.5mm, 19.5mm, and 25mm coarse aggregate were 60, 100, and 90. The workability decreased with slight differences when the coarse aggregate size was increased. Three different sizes of coarse aggregates with 25mm maximum size for both processed (granite) and sand stone (Local stone) were employed in the investigation, namely; 12.5mm, 19.5mm and 25mm. The grading and relative densities of the aggregates were studied. The mix ratio and water / cement ratio adopted for the study was 1:2:4 and 0.5 respectively. Twelve concrete cubes (72 total) (150mm× 150mm×150mm) were cast for each coarse aggregate size and type of which three were crushed at each maturity age namely; 7, 14, 21 and 28 days. The 28 day strength…

In this paper, some methods of lightning protection measures are expounded in this paper, and then the influence of grounding resistance on ground resistance with current changing with current is revised by means of incomplete consideration of the influence factors of the impact grounding resistance in the standard.

Under the action of low pressure, the wheel pile foundation bears most or even all the downward pressure. When the wheel pile foundation is subjected to uplift force, the uplift force is supported by the short pile, and the ring frame and the 4 flange mainly play the role of transfer pulling force, while the main bearing force is short and short pile. When the wheel pile foundation is subjected to horizontal forces, the horizontal force is mainly borne by the flange and the ring frame. Therefore, only downward pressure and horizontal force should be considered for the ring frame and flange, while uplift force should be considered for the design of thin and short piles. The basic design is simple and the transmission path is clear. The ring frame, flange and short pile of the wheel pile foundation are prefabricated. The foundation can take different prefabricated installation methods with the mechanized construction conditions. It can not only guarantee the quality of the concrete slab, but also speed up the construction speed of the foundation. By comparing with the economic technology of the plate foundation, it is found that under the same geological conditions, the use of wheel pile foundation can reduce the concrete earthwork and the increase of the load, the decrease of concrete is also increased, and the amount of steel is saved, and the economic benefit is remarkable.

In this paper, a general kinematic model of the four drive wheel omnidirectional mobile platform is established, and the CMAC (Cerebellar model articulation controller) +PID joint control strategy is used to design the embedded adaptive control of the omnidirectional mobile platform in view of the problem that the conventional control can not be self-tuning online and the real-time response of the response needs to be improved. The MATLAB simulation and experimental analysis of DC motor speed regulation were carried out, and the motion performance of the prototype was tested by a series of typical experiments. The results show that the kinematic model of the mecanum wheel omnidirectional moving platform is reasonable. The dynamic response of the CMAC+PID adaptive controller is fast, the control precision is high, and the robustness is good. The prototype can achieve the horizontal / vertical translation, the original rotation and the omni-directional motion in the plane. The overall performance can meet the requirements of the engineering application.

Introduction: Poor oral hygiene is common in ICU patients, which leads to colonization of the oral biofilm by pathogenic microorganisms, especially respiratory pathogens, which may be a source of nosocomial infection. Once the bacteria present in the mouth can be aspirated and cause aspiration pneumonia. Objective: Review of the literature regarding the importance of dental intervention in patients hospitalized in intensive care units. Methodology: An integrative review was carried out in the LILACS databases and in the SCIELO Virtual Library, using the descriptors: Dental care, Periodontal diseases and ICU. Inclusion criteria were: full-text articles available in Portuguese or English and with a temporal cut between 2013 and 2017. Results: Three articles were selected to meet the criteria for inclusion. Discussion: The oral cavity is the first portal of entry for respiratory pathogenic organisms that cause systemic infections, with pneumonia being one of them. Aspiration pneumonia is the most common type of nosocomial or hospital pneumonia and is an infection of the pulmonary parenchyma caused by different types of etiological agents including bacteria, fungi and viruses. This disease is of high cost and represents a significant cause of morbidity and mortality, diagnosed 48 hours after the patient’s hospitalization in the ICU. The absence of attention with oral hygiene and the reduction of salivary flow results in an increase in the quantity and complexity of dental plaque, which may favor bacterial interaction between native plaque bacteria and respiratory pathogens such as P. aeruginosa and enteric bacilli. Conclusion: The evaluation of the oral condition and the need for dental treatment in hospitalized patients require follow-up by a dental surgeon qualified in hospital dentistry avoiding an increase in the proliferation of fungi and bacteria and, consequently, infections and systemic diseases.

Introduction: Sleep bruxism is an activity of stereotyped movements promoted by the subconscious in the masticatory system that includes the functions of clenching and / or grinding, where neuromuscular protection mechanisms are absent, which can lead to damages to the masticatory system and temporomandibular disorders. Aim: This article aims to demonstrate conducts used in a clinical case to assist in similar case planning. Case report: A 58-year-old male patient required an appointment at the Federal University of Pernambuco integrated dentistry clinic, presenting a complaint of pain in the face region and lack of adaptation with prostheses, he had posterior maxillary edentulism, loss of vertical dimension and severe wear on the remaining teeth. The anamnesis was made in his initial clinical examination, later, was prepared the diagnostic wax-up, the waxing was moulded with condensation silicone for restoration in composite resin with prefabricated pins. Afterward the molding were made to prepare removable partial dentures for the patient. In the old prostheses overlays were prepared to slide between them forming a type of plaque, reprogramming the jaw and avoiding that the patient destroyed the already made restorations. In the following session, the well-adapted prostheses were delivered and the occlusal adjustment was properly performed with intraoral test. Results: The patient reported aesthetic improvement, total pain reduction and better adaptation with the prostheses, he also related comfort in using them. Conclusion: It is possible to perform the rehabilitation of partial edentulous bruxers, approximating the patient to his or her centric relation, without the necessity of plaques and maintaining a quality treatment.

Introduction: Obstructive sleep apnea (OSA) is a respiratory disorder that causes upper airway obstruction during sleep. The performance of a dentist in patients with OSA is evidenced by the preparation and indication of the Oral Appliances (OA) as a treatment measure. The OAs are devices used in the oral cavity during sleep avoiding an obstruction of the oropharynx. These are classified as lingual, mandibular and/or conjugate control devices. Objective: To describe the OA models and to make explicit the indication of each one for the type of apnea in question. Methodology: A database was searched (Pubmed, Scielo) using the following documents: Intraoral device, lingual control, mandibular advancement, indication. Publications from 2010 to 2017 were included in the Portuguese and English languages whose content was pertinent to the theme. Results and Discuss: 60 articles were found. Of these, 24 directly addressed the theme and only 4 articles were used. A practicality and comfort provided by the OAs make them more accepted and indicated for OSA. The indications for the use of OAs include: patients with the diagnosis of mild, moderate and severe OSA. The lingual control device is based on control of the positioning of the aforementioned organ and is indicated for patients with extensive dental loss, edentulous, periodontal problems, temporomandibular dysfunction and bruxism. The most commonly indicated mandibular advancement OA is retained by teeth and protrudes the mandible in order to increase the volume of the oropharynx. Ideal for patients with at least 10 teeth in each arch and on a semi-flexible model for transport conditions, small mandibular movements. Conclusion: The indication of AIO depends on the oral cavity conditions and the general health of the patient and are potentially capable of improving the quality of life of an OSA carrier.

The mine of Trepca in Stanterg has had a big economic importance since the earlier period to now. Even if there is not any written source about the development in this times, some signs prove the begining of the mine activities since the ilyrian period. The archelogyc documents prove the cink and leaden in TREPCA, are used for more than 2000 years. The documents of middle ages prove that the namr of “Trepca” for the first is mentioned in the Dubrovnik’s archive in 1303. In this study we’re going to treat the destroyment of Trepca, during the Ottoman leading since 1445 till the 20th cebtury. The historical importance of Trepca’s mine is Stanterg is a big and valuable as it is impossible to describe it in a few words. However, I have tried to show it is a science manner and as a historical, economic and social issue during the 20th century.

Physicists measured the propagation of light in vacuum and matter through experiments with light over the course of several centuries. The Laws of Optics were derived from these measured results. The Laws of Optics were verified repeatedly via real experiments with light and used in the calculations of optical instruments that work properly. The Laws of Optics accurately define the propagation of light in vacuum and matter. All the theories of the propagation of light that ignore the Laws of Optics can, therefore, be considered an error in physics. The theories and laws of propagation of light in matter were written by famous physicists, such as Isaac Newton (1670), Christiaan Huygens (1650), Augustin-Jean Fresnel (1819), and Thomas Young (1800). The law of propagation of light in matter was described by Snell in 1620. Snell’s law is the law of the light refractive index in matter. Optical instruments are calculated according to the Laws of Optics, so by their correct operation they confirm the validity of the Laws of Optics. Two hundred years ago, André-Marie Ampére expressed the basic approach in discovering the laws of physics: “First observe the facts, to vary their circumstances as much as possible, to accompany this first task with exact measurement so as to deduce from them the general laws based solely upon experience, and to deduce from these laws, independently of any hypothesis on the nature of the forces that produce the phenomena, the mathematical value of these forces”. This approach to the measurement of the light propagation is now used in all the laboratories around the world and, therefore, can be considered as objective and accurate.