Effects of the granule composition on the compaction behavior of deformable dry granules

Calibration of the Drucker Prager Cap (DPC) model parameters provides a means for a deeper understanding of the impact of granule composition on the compaction properties of dry granules independent of their solid fraction (SF). In this study, monodisperse granules of mixtures of microcrystalline cellulose and mannitol (0%, 25%, 50%, 75% and 100% mannitol) prepared as small cylindrical compacts with well-defined size, shape and SF (0.58) were used as model dry granules. DPC parameters--namely, cohesion, internal friction angle, cap eccentricity, and hydrostatic yield strength of materials--were determined from the diametrical and uniaxial compression, and in-die compaction tests. Elastic properties such as Young’s modulus and Poisson’s ratios were also determined from the in-die compaction test. Higher level of MNT in granules required a lower compression pressure to obtain a low SF tablet but higher compression pressure to obtain a high SF tablets. Properties such as cohesion and diametrical tensile strength go through a maximum as the mannitol level increases in the binary granules, and clearly do not follow the linear mixing rule. At an industrially-relevant tablet solid fraction of 0.88, granules with 75% mannitol exhibited the highest cohesion, and produced the strongest tablet. Other properties either approximately follow the linear mixing rule (e.g., hydrostatic yield strength, young's modulus and Poisson’s ratio) where some interactions between the constituents are present, or not sensitive to the composition (e.g., internal angle of friction). In general, the compaction behavior of granules of a multicomponent system may not be precisely estimated from the properties of individual components, simply by using the linear mixing rule

Compaction mechanics of plastically deformable dry granules

To improve the understanding of how dry granulation and in particular, granule solid fraction (SF) impact the compaction behavior of plastically deformable microcrystalline cellulose (MCC), in this study, the Drucker Prager Cap (DPC) model parameters were calibrated using monodisperse MCC dry granules as model granules. Dry granules were produced as directly compressed small cylindrical compacts of MCC with SF in the range of 0.40 to 0.70 which were monodisperse in both size and SF. Virgin MCC powder and granules were compressed into tablets with SF in the range of 0.70 to 0.90. The DPC parameters (cohesion, internal friction angle, cap eccentricity, and hydrostatic yield stress), Young's modulus and Poisson's ratio were experimentally determined from diametrical and uniaxial compression, and in-die compaction tests. Results showed that calibration of the shear failure surface only may be adequate for MCC granules when the DPC model is completely calibrated for virgin MCC. Increasing granule SF significantly decreased the cohesion only. All other parameters were impacted by the tablet SF only. In the 2D yield surface, only the shear failure surface expanded as the granule SF increased. MCC of any granulation status requires the same in-die compaction stress state for densification to a given tablet solid fraction

The Grizzly, September 4, 2003

A Space to Call Your Own • Pay for Print Solution • Bumpy Ride • Spotlight on Politics: The California Recall • Feeling Disconnected: Internet and Virus Woes • A Plan for Every Future: Career Services Fall 2003 • Opinions: Campus Rooms: Is Space Running Out?; Network Gripes Getting you Down? Elections in California: Business as Usual or Free for All? • Activities, Activities, Activities • Calling all Thespians! • Ursinus in 1893: What was it Like? • New Arts Center • Local Heritage Day Celebration • Bears Versatility Makes the Season Look Promising • UC Field Hockey Team: Ready to Rumble • Promising Season Abound for the Men and Women\u27s Soccer Teams • Ursinus Cross Country Kicks-off • Ursinus Volleyball Team Off to Rough Start • X-Country Team Scoreshttps://digitalcommons.ursinus.edu/grizzlynews/1539/thumbnail.jp

The Grizzly, October 16, 2003

Feeling Drained for a Good Cause: Omega Chi Blood Drive • CAB Laugh-off Left Students Rolling in the Aisles • UC in the City Program Announces Easier Access to Philly • Political Pagemakers: Democratic Candidates for President • California Recall Circus has its Star • Club Spotlight: Forensics • Opinions: UC in the City: An Attempt to Fight the Boredom; California Recall Election Democracy at its Best; Video Games as Government Training Tools; Flu Season is Near; Legal BAC Should Still be Lower; Myrin Library: Use It • On the Verge Review: Memorable • Believe it or Not: A Tree in the End Zone • Meet Dr. Zwerling • Job Fair Success • 2003 Homecoming Court • Women\u27s Rugby: A Tough and Spirited Group of Ladies • Field Hockey Team Remains Undefeated in Conference • Men\u27s Soccer Continues to Face Tough Losses • Volleyball 2-3 in Conference Play • Sue Hadfield Named Head Swimming Coachhttps://digitalcommons.ursinus.edu/grizzlynews/1545/thumbnail.jp

The Grizzly, November 6, 2003

Ursinus to Take its Place in the Future • Sticks and Stones: Hate Speech on Campus • Students Bug Out after Insect Invasion • Election Day: Mud Slinging and Politics • Look Back at October: Breast Cancer Month • Opinions: OCD: Harmless Passions or Medical Disorder?; Struggling with OCD, the Disorder; Finding Ways to Cope with the Parting of a Pet; Rush Limbaugh: Another Conservative Hypocrite; Pot Smoking Equals Lower Stamina?; Registering Online: An Extreme Inconvenience • Poet Comes to U.C. • Careers in Criminology and Investigation • Meet Dr. Kozusko: The New Shakespeare Professor • Perceptions of Greeks in the Media, UC • Greek Life Fifty Years Ago • Rushing: Is it for You? • Despite Loss, UC Football Team Remains Hopeful • UC XC Competes in Centennial Conference Championship • UC XC Holds 18th Annual Bear Pack Run 5K • Athletic Profile: Katie Dougherty • Women\u27s Rugby Team Makes History • UC Soccer Updateshttps://digitalcommons.ursinus.edu/grizzlynews/1547/thumbnail.jp

Correlates of Health-Protective Behavior During the Initial Days of the COVID-19 Outbreak in Norway

The coronavirus outbreak manifested in Norway in March 2020. It was met with a combination of mandatory changes (closing of public institutions) and recommended changes (hygiene behavior, physical distancing). It has been emphasized that health-protective behavior such as increased hygiene or physical distancing are able to slow the spread of infections and flatten the curve. Drawing on previous health-psychological studies during the outbreak of various pandemics, we investigated psychological and demographic factors predicting the adoption and engagement in health-protective behavior and changes in such behavior, attitudes, and emotions over time. We recruited a non-representative sample of Norwegians (n = 8676) during a 15-day period (March 12–26 2020) at the beginning of the COVID-19 outbreak in Norway. Employing both traditional methods and exploratory machine learning, we replicated earlier findings that engagement in health-protective behavior is associated with specific demographic characteristics. Further, we observed that increased media exposure, perceiving measures as effective, and perceiving the outbreak as serious positively was related to engagement in health-protective behavior. We also found indications that hygiene and physical distancing behaviors were related to somewhat different psychological and demographic factors. Over the sampling period, reported engagement in physical distancing increased, while experienced concern or fear declined. Contrary to previous studies, we found no or only small positive predictions by confidence in authorities, knowledge about the outbreak, and perceived individual risk, while all of those variables were rather high. These findings provide guidance for health communications or interventions targeting the adoption of health-protective behaviors in order to diminish the spread of COVID-19

Correlates of Health-Protective Behavior During the Initial Days of the COVID-19 Outbreak in Norway

The coronavirus outbreak manifested in Norway in March 2020. It was met with a combination of mandatory changes (closing of public institutions) and recommended changes (hygiene behavior, physical distancing). It has been emphasized that health-protective behavior such as increased hygiene or physical distancing are able to slow the spread of infections and flatten the curve. Drawing on previous health-psychological studies during the outbreak of various pandemics, we investigated psychological and demographic factors predicting the adoption and engagement in health-protective behavior and changes in such behavior, attitudes, and emotions over time. We recruited a non-representative sample of Norwegians (n = 8676) during a 15-day period (March 12–26 2020) at the beginning of the COVID-19 outbreak in Norway. Employing both traditional methods and exploratory machine learning, we replicated earlier findings that engagement in health-protective behavior is associated with specific demographic characteristics. Further, we observed that increased media exposure, perceiving measures as effective, and perceiving the outbreak as serious was positively related to engagement in health-protective behavior. We also found indications that hygiene and physical distancing behaviors were related to somewhat different psychological and demographic factors. Over the sampling period, reported engagement in physical distancing increased, while experienced concern or fear declined. Contrary to previous studies, we found no or only small positive predictions by confidence in authorities, knowledge about the outbreak, and perceived individual risk, while all of those variables were rather high. These findings provide guidance for health communications or interventions targeting the adoption of health-protective behaviors in order to diminish the spread of COVID-19