scholarly journals Investigation on the Flexural Modulus of Silicon Dies to Improve Die Mechanical Modeling Accuracy

2021 ◽  
pp. 57-64
Author(s):  
Jefferson Talledo
Keyword(s):  
Integrated Circuit ◽  
Flexural Modulus ◽  
Back Side ◽  
Mechanical Modeling ◽  
Bulk Silicon ◽  
Significant Difference ◽  
Modeling Accuracy ◽  
The Common ◽  
Point Bend ◽  
Die Deflection

Mechanical modeling of integrated circuit (IC) dies is commonly performed using the mechanical properties of the bulk silicon material. However, modeling results such as die deflection and the actual results were observed to have significant difference. This paper discusses the investigation done on the flexural modulus of actual IC dies used in package assembly manufacturing. Results were then compared with the modulus of the bulk silicon die or mirror die. The measurement of flexural modulus was done using the standard 3-point bend test. It was found out that the flexural modulus of the actual IC die is significantly lower than the flexural modulus of the bulk silicon or dummy die. Even with the actual IC die, the flexural modulus of the active side is also lower than the back side. From this study, it can be concluded that mechanical modeling involving IC dies could be improved by characterizing the properties of the actual die used. The common practice of using the properties of the bulk silicon die in mechanical modeling would not provide accurate results.

scholarly journals Fracture Strength Characterization of the Die Active Side and Back Side for a Realistic Die Crack Assessment

2021 ◽  
pp. 84-90
Author(s):  
Jefferson Talledo
Keyword(s):  
Fracture Strength ◽  
Integrated Circuit ◽  
Back Side ◽  
Circuit Layout ◽  
The Common ◽  
Point Bend Test ◽  
The Difference ◽  
Point Bend ◽  
Strength Characterization

This paper discusses the characterization of an integrated circuit (IC) silicon die fracture strength to have a realistic die crack assessment. The evaluation was conducted using a 3-point bend test setup to measure the die strength of actual IC dies. Both the active side and the back side of the IC die were tested for 2 types of dies with different active side circuit layout. Results showed that the difference in the die active side circuit layout or structure has impact on die strength. It was also found that the active side was weaker than the back side. This implies that both the active side and the back side of an actual IC die must be subjected to fracture strength characterization to have an assessment that would be in a better agreement with real condition. Using only the strength of the back side would result in over-estimating the die strength. The common approach of using the fracture strength of the die back side to characterize the die strength is not realistic and can mislead the assessment of die crack or semiconductor package robustness.

scholarly journals Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1745
Author(s):  
Tamaki Hada ◽  
Manabu Kanazawa ◽  
Maiko Iwaki ◽  
Awutsadaporn Katheng ◽  
Shunsuke Minakuchi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Sorption ◽  
Water Solubility ◽  
Flexural Modulus ◽  
Manufacturing Method ◽  
Heat Curing ◽  
Significant Difference ◽  
Cad Cam ◽  
Curing Method

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

INCIDENCE OF CRANIAL NERVE PARALYSIS IN POLIOMYELITIS IN RELATION TO PRESENCE OR ABSENCE OF TONSILS

PEDIATRICS ◽  
1958 ◽  
Vol 21 (1) ◽  
pp. 94-105
Author(s):  
F. H. Top
Keyword(s):  
Facial Nerve ◽  
Cranial Nerves ◽  
Age Group ◽  
Real Difference ◽  
Satisfactory Explanation ◽  
Nerve Paralysis ◽  
Cranial Nerve Paralysis ◽  
Significant Difference ◽  
The Central Nervous System ◽  
The Common

Evidence is presented from data covering the period 1940 to 1952 which corroborates the conclusion of previous studies that prior tonsillectomy probably adversely affects the occurrence of brainstem paralysis (bulbar and bulbospinal) in poliomyelitis. Neither this study nor any preceding studies relating to this problem have proved the contention. On the basis that the hypothesis is correct, an attempt is made to find an answer by studying the incidence of the common paralysis of cranial nerves (VII, IX and X and XI) in bulbar and bulbospinal cases of poliomyelitis on the basis of presence or absence of tonsils. Rates of incidence of paralysis of cranial nerves, not adjusted for age, indicate a decidedly higher proportion of paralysis of the facial nerve (VII) among nontonsillectomized patients whereas tonsillectomized persons are preportionately more affected by palatal and pharyngeal paralysis (nerves IX and X). Paralysis of the facial nerve appears from two studies to occur more commonly at earlier ages, particularly in the age group 0 to 4 years. However, age adjustment did not erase, although it did somewhat lower, the TR/TP ratio. This finding lends credence to a real difference but can only be applied to this study, as Paffenbarger in a smaller study found no significant difference in frequencies of paralysis of the facial nerve between groups with tonsils removed and tonsils present, and Southcott, also in a small study, found paralysis of the facial nerve more common among tonsillectomized patients with bulbar (includes bulbospinal) involvement. The differences noted for palatal and pharyngeal paralyses (nerves IX and X) in the unadjusted rates as between tonsillectomized and nontonsillectomized patients remain statistically different and in some instances significant when corrections for age are made. The results of this study are suggestive but give no entirely satisfactory explanation for the differences noted. Various explanations previously offered are cited and briefly discussed. Perhaps more definitive studies in animals along the approach suggested by Southcott will prove more fruitful, namely, labelling virus by some radioactive element in order to trace the route it takes to the central nervous system.

Correlation Between Intestinal Microflora and Gastrointestinal Dysfunction in Elderly Patients with Sepsis

2020 ◽  
Vol 12 (8) ◽  
pp. 1030-1037
Author(s):  
Hailing Yang ◽  
Xiaolin Zhang ◽  
Weijun Chen ◽  
Libo Shang ◽  
Bin Chen ◽  
...  
Keyword(s):  
Elderly Patients ◽  
Intestinal Microflora ◽  
Sepsis Group ◽  
Control Group ◽  
Gastrointestinal Dysfunction ◽  
E Coli ◽  
Significant Difference ◽  
Prevention And Treatment ◽  
The Common ◽  
Wbc Count

Multiple organ dysfunction syndrome (MODS) is a key factor that leads to death in elderly patients with sepsis. Therefore, early prevention and treatment of gastrointestinal dysfunction (GIDF) in elderly patients with sepsis is an important measure to prevent MODS occurrence. This research explores the correlation between intestinal microflora and GIDF in elderly patients with sepsis and provides ideas for the prevention and treatment of GIDF in elderly patients with sepsis. In this study, 152 patients with sepsis (122 patients with sepsis and GIDF) treated in the Third Affiliated Hospital of Yunnan University of Chinese Medicine from January to September 2019 were selected as the sepsis group and 100 elderly who had normal physical examination results were selected as the control group. The common intestinal microflora of the two groups was compared. Patients with sepsis and GIDF were treated as the GIDF group and the other patients with sepsis were treated as the non-GIDF group. The common intestinal microflora, gastrointestinal indicators, serum inflammatory factors, and immune function indices were compared between the two groups. Correlation analysis of the observed indices with statistical significance was carried out. The results showed 152 patients with sepsis and 122 patients with sepsis and GIDF; thus, the incidence of sepsis with GIDF was 80.26%. The total average score of sepsis with GIDF was 3.61±0.09. There was no statistically significant difference in GIDF scores of patients ages 65–75 and > 75 years old. The number of Bifidobacterium and Lactobacillus in elderly patients with sepsis was lower and the number of Escherichia coli was higher than in the control group. In elderly patients with sepsis, the number of Bifidobacterium and Lactobacillus in the GIDF group was lower and the number of E. coli was higher than in the non-GIDF group. White blood cell (WBC) count, procalcitonin (PCT), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), gastrin (GAS), and diamine oxidase (DAO) in GIDF patients were higher and motilin (MOT), CIT (CIT), CD4+, and CD8+ were lower than in the non-GIDF group. WBC count, PCT, CRP, TNF-α, GAS, and DAO were negatively correlated with the number of Bifidobacterium and Lactobacillus but positively correlated with E. coli. MOT, CIT, CD4+, and CD8+ were positively correlated with the number of Bifidobacterium and Lactobacillus but negatively correlated with E. coli. There was a negative correlation between Bifidobacterium and Lactobacillus and GIDF score and a positive correlation between E. coli and GIDF score. Therefore, the change in the intestinal microflora in elderly patients with sepsis is related to GIDF.

scholarly journals Cervical spine dysfunction signs and symptoms in individuals with temporomandibular disorder

2012 ◽  
Vol 24 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Priscila Weber ◽  
Eliane Castilhos Rodrigues Corrêa ◽  
Fabiana dos Santos Ferreira ◽  
Juliana Corrêa Soares ◽  
Geovana de Paula Bolzan ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Temporomandibular Disorder ◽  
Signs And Symptoms ◽  
Cervical Pain ◽  
Pain Symptom ◽  
Significant Difference ◽  
The Common ◽  
Cervical Spine Dysfunction ◽  
Posture Assessment ◽  
Craniocervical Dysfunction

PURPOSE: To study the frequency of cervical spine dysfunction (CCD) signs and symptoms in subjects with and without temporomandibular disorder (TMD) and to assess the craniocervical posture influence on TMD and CCD coexistence. METHODS: Participants were 71 women (19 to 35 years), assessed about TMD presence; 34 constituted the TMD group (G1) and 37 comprised the group without TMD (G2). The CCD was evaluated through the Craniocervical Dysfunction Index and the Cervical Mobility Index. Subjects were also questioned about cervical pain. Craniocervical posture was assessed by cephalometric analysis. RESULTS: There was no difference in the craniocervical posture between groups. G2 presented more mild CCD frequency and less moderate and severe CCD frequency (p=0.01). G1 presented higher percentage of pain during movements (p=0.03) and pain during cervical muscles palpation (p=0.01) compared to G2. Most of the TMD patients (88.24%) related cervical pain with significant difference when compared to G2 (p=0.00). CONCLUSION: Craniocervical posture assessment showed no difference between groups, suggesting that postural alterations could be more related to the CCD. Presence of TMD resulted in higher frequency of cervical pain symptom. Thus the coexistence of CCD and TMD signs and symptoms appear to be more related to the common innervations of the trigeminocervical complex and hyperalgesia of the TMD patients than to craniocervical posture deviations.

scholarly journals Evaluación del perfil de egreso y prácticas profesionales en estudiantes de Pedagogía en Educación Básica, en la Universidad Católica Silva Henríquez (UCSH), 2009

2014 ◽  
pp. 175
Author(s):  
Susana Barrera A.
Keyword(s):  
Elementary Education ◽  
Initial Teacher Training ◽  
University Mathematics ◽  
Science And Art ◽  
Palabras Clave ◽  
Significant Difference ◽  
General Training ◽  
The Common ◽  
Key Words Evaluation ◽  
Formación Docente

RESUMEN Esta investigación se propone diagnosticar el logro de competencias del perfil de egreso alcanzado por estudiantes, y las dificultades en sus prácticas pedagógicas, en la carrera de Pedagogía en Educación Básica, con referencia en los Planes Comunes de Universidad (PCU) y de Educación (PCEDUC), y las áreas de formación generalista. Utiliza tests, con ítems problematizadores donde el evaluado aplica habilidades formadas. Los resultados corresponden a 66 voluntarios, de 98 egresados. En PCEDUC y Ciencias Naturales más de la mitad de egresados alcanzan logros regularmente suficientes; en PCU, Matemática, Ciencias Sociales y Educación Artística se concentran logros insuficientes, mientras que en Lenguaje un tercio evidencia logros suficientes. No hay diferencia significativa en los resultados de Programa por jornadas. En las prácticas se destacan problemas en la supervisión, manejo de estrategias de enseñanza y de convivencia. Palabras clave: Evaluación de logros, perfil de egreso, formación docente, práctica profesional  ABSTRACT The purpose of this research is to diagnose the achievement of the competences of the graduate profile achieved by students and the difficulties in their internships regarding the Program of Education in Elementary Education, with reference to the Common Plan of University (PCU) and Common Plan of Education (PCEDUC), and the areas of general training. It uses tests, with items in context where he applies the skills acquired. Results correspond to 66 volunteers of 98 graduates. In the Common Plan Education and Natural Sciences for more than half of graduates achieve regularly sufficient progress, in Common Plan University, Mathematics, Social Science and Art focus on insufficient achievements, while one third show enough achievements on Language. There is no statistically significant difference in results by the type of Program. In the internships, stand out problems with supervision, the managing strategies, and the school coexistence. Key Words: Evaluation of achievements, graduate profile, initial teacher training, internships.

scholarly journals Using a smartphone video camera to reduce anxiety in speaking activity

2021 ◽  
Vol 12 (1) ◽  
pp. 38-55
Author(s):  
Nur Asma
Keyword(s):  
Smartphone Application ◽  
Video Camera ◽  
New Methods ◽  
Self Confidence ◽  
Significant Difference ◽  
English Speaking ◽  
The Common ◽  
Common Problems ◽  
And Control ◽  
Relevant Factors

The common problems faced by students in English speaking are anxiety and the lack of confidence and ideas. This research was conducted to determine the relevant factors and to provide a solution by using the smartphone video camera. To obtain the data in this research, experimental research was performed inside and outside the classroom with a series of treatments and a questionnaire sheet as the instrument. The data were analyzed using a model proposed by Smeda, Dakich, and Sharda (2014) and a Likert scale questionnaire, which was adapted from Spratt, Humphreys, and Chan (2002). The result from the test showed a significant difference between the experimental and control classes as the carried t-test presented the score of -8.36, which was out of the limit (between -1.96 and 1.96). Another result was the students developed positively which was shown by: the anxiety tends to decrease as they were given time before performing thus prepared better, their self-confidence was increased and challenged by using the smartphone video camera method due to the application of innovation in the speaking class. The conclusion of this research is lecturer needs to apply new methods, one of which is using a smartphone application.

scholarly journals An Analysis of Students’ Grammatical Errors in Writing Procedure Texts

2021 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Ihda Husnayaini ◽  
M Thaib Rizki ◽  
Chindy Savitri
Keyword(s):  
Research Method ◽  
Female Students ◽  
Male And Female ◽  
Paired Sample ◽  
9Th Grade ◽  
Significant Difference ◽  
Grammatical Errors ◽  
Procedure Text ◽  
The Common ◽  
Result Analysis

This study investigated the common types of grammatical errors made by 3rd grade of secondary male and female students at SMP Muhammadiyah Pangkalpinang in writing procedure texts and to find out whether there was any significant difference in the errors committed by the students when grouped according to gender. The researcher specified this study in writing procedure text which focused on their errors. The research method used was quantitative. The samples of this study were 30 students that were taken from 9th grade of SMP Muhammadiyah Pangkalpinang. The data was obtained from the sentences written by the students and by means of the test. In this study, the result of the test was analyzed by paired sample t-test. In accordance with the result analysis, the study revealed two major findings. The result showed that there was a significant difference in the errors committed by the students when grouped according to gender. Therefore, the data further means that gender affects the number, and percentage of errors committed by the students.

scholarly journals Properties of Composite Materials Used for Bracket Bonding

2013 ◽  
Vol 24 (3) ◽  
pp. 279-283 ◽  
Author(s):  
Ana Caroline Silva Gama ◽  
Andre Guaraci de Vito Moraes ◽  
Lilyan Cardoso Yamasaki ◽  
Alessandro Dourado Loguercio ◽  
Ceci Nunes Carvalho ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Stress Test ◽  
Flexural Modulus ◽  
Significant Difference ◽  
Contraction Stress ◽  
Materials Used ◽  
Flowable Composites

The purpose of this study was to evaluate in vitro the shear bond strength to enamel, flexural strength, flexural modulus, and contraction stress of one orthodontic composite and two flowable composites. Orthodontic brackets were bonded to 45 human maxillary premolars with the composites Transbond XT, Filtek Z-350 flow and Opallis flow and tested for shear bond strength. For measurement of flexural strength and flexural modulus, specimens were fabricated and tested under flexion. For the contraction stress test, cylindrical specimens were tested and an extensometer determined the height of the specimens. The data were subjected to one-way ANOVA and Tukey's test (α=0.05). The shear bond strength values were significantly lower (p<0.05) for the flowable composites compared with the orthodontic composite. For the flexural strength, no statistically significant difference was found among the composites (p>0.05) while the flexural modulus was significantly higher (p<0.05) for Transbond XT than for Filtek Z-350 flow and Opallis flow. The orthodontic composite presented significantly lower contraction stress values than the flowable composites (p<0.05). The light-activated orthodontic composite material presented higher flexural modulus and shear bond strength and lower contraction stress than both flowable composites.

scholarly journals Effect of graded nerve pressure injuries on motor function

2015 ◽  
Vol 122 (6) ◽  
pp. 1438-1443 ◽  
Author(s):  
Mika Karasawa ◽  
Kumiko Yokouchi ◽  
Akira Kakegawa ◽  
Kyutaro Kawagishi ◽  
Tetsuji Moriizumi ◽  
...  
Keyword(s):  
Nerve Injury ◽  
Motor Function ◽  
Lower Limb ◽  
Peroneal Nerve ◽  
Tibialis Anterior Muscle ◽  
Common Peroneal Nerve ◽  
Nerve Fibers ◽  
Walking Ability ◽  
Significant Difference ◽  
The Common

OBJECT The purpose of this study was to determine the minimum amount of nerve fibers required to maintain normal motor function after nerve injury in rats. METHODS The authors first confirmed that a common peroneal nerve injury caused more aggravating effects on lower limb motor function than tibial nerve injury, as assessed by the static sciatic index (SSI). Thereafter, rats were subjected to varying degrees of crush injury to the common peroneal nerve. At 48 hours after the injury, motor function was assessed using the SSI and slope-walking ability (with slope angles of 30° and 45°). The tibialis anterior muscle, a main muscle innervated by the common peroneal nerve, was removed. Muscle sections were co-labeled with neuronal class III β-tubulin polyclonal antibody to identify the presence of axons and Alexa Fluor 488-conjugated α-bungarotoxin to identify the presence of motor endplates. RESULTS The evaluation of neuromuscular innervation showed a correlation between SSI scores and ratios of residual axons (rs = 0.68, p < 0.01), and there was a statistically significant difference between slope-walking ability and ratios of residual axons (p < 0.01). Moreover, the ratios of residual axons in the nerve-crushed rats with normal motor function (SSI above −20) ranged from 36.5% to 88.7%, and those ratios in the success group with slope-walking angles of 30° and 45° ranged from 14.7% to 88.7% and from 39.8% to 88.7%, respectively. CONCLUSIONS In this study of rodents, less than half of the motor axons were sufficient to maintain normal motor function of the lower limb.

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